work, power, and energy mrs sedlock principles of chemistry and physics
TRANSCRIPT
![Page 1: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/1.jpg)
Work, Power, and Energy
Mrs SedlockPrinciples of Chemistry and Physics
![Page 2: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/2.jpg)
Review
• Newton’s Laws were used to predict and describe an object’s motion
• In this unit we will discuss motion in terms of energy and work
![Page 3: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/3.jpg)
Work
• Work - when force acts on an object and causes displacement of the object – Force– Displacement– Cause • In order for work to be done there must be a force that
causes a displacement
![Page 4: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/4.jpg)
Examples of Work
![Page 5: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/5.jpg)
Examples of work
A teacher applies a force to a wall and becomes exhausted. A book falls off a table and free falls to the ground. A waiter carries a tray full of meals above his head by one arm straight across the room at constant speed. (Careful! This is a very difficult question that will be discussed in more detail later.) A rocket accelerates through space.
![Page 6: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/6.jpg)
Work
• Any part of a force that does not act in the direction of motion does NO WORK in an object
![Page 7: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/7.jpg)
Negative Work
• Sometimes force acts in the opposite direction of the displacement to prevent motion– Ex: • car skidding to a stop• Baseball player sliding into home plate
![Page 8: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/8.jpg)
Calculating Work
• Work = force x displacement
• Unit of work = J (Joules)• 1 J = 1 N*m
• Ws work problems
![Page 9: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/9.jpg)
Power
![Page 10: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/10.jpg)
Power
• Power – is the rate of doing work– Doing work at a faster rate requires more power– to increase power, increase the amount of work
done in a given amount of time – Or do the same amount of work in less time
![Page 11: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/11.jpg)
Power
• The snow blower can do more work in less time – so it has more power than the person shoveling
![Page 12: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/12.jpg)
Calculating Power
Power = work time
Units Work is in Joules (J)Time is in seconds (s)Power is in watts (W) which is 1 Joule /second
Ex: a 40-watt lightbulb requires 40 Joules each second that it is lit
![Page 13: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/13.jpg)
Calculating Power
• You exert a vertical force of 72 Newtons to lift a box to a height of 1.0 meter in a time of 2.0 seconds. How much power is used to lift the box?
• (hint: remember that work = force x displacement )
• 36 Watts
![Page 14: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/14.jpg)
Horsepower
• One horsepower (hp) = 746 Watts
![Page 15: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/15.jpg)
• slapshot physics
![Page 16: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/16.jpg)
Work and Machines
drones
![Page 17: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/17.jpg)
Machine
• Machines make work easier to do – Change the size of the force – Or the direction of the force– Or distance over which a force acts
![Page 18: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/18.jpg)
• Increase force• Each rotation applies a small force over a large
distance, but each rotation lifts the car a short distance
• If a machine increases the distance over which you exert a force, then it decreases the amount of force you need to exert
![Page 19: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/19.jpg)
![Page 20: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/20.jpg)
• Increasing distance• The oars act as a machine to push the boat
through the water • Pulling the oar short distance near the boat
translates to a large distance in the water – but you increase the force needed
• A machine that decreases the distance through which you exert a force increases the amount of force
![Page 21: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/21.jpg)
![Page 22: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/22.jpg)
• Change of direction• Some machines change the direction of the
applied force• Pulling back on the handle of the oar causes
its other end to move the opposite direction
• Machines can change the direction of the force
![Page 23: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/23.jpg)
Work Output
• The force that is exerted by a machine is called the output force
• The distance the output force is exerted through is the output distance
• work output = output force x output distance•
![Page 24: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/24.jpg)
Work Input and Work Output
• Because of friction, the work done by a machine is always less than the work done on the machine
![Page 25: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/25.jpg)
Work input and work output
• The force you exert on a machine is called the input force
• the distance the input force acts through is called the input distance
• The work done in this process is called the work input
• Work input = input force x input distance
![Page 26: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/26.jpg)
Work Input
• For the oar- – the input force is the force exerted on the handle – The input distance is the distance the handle
moves– The work input is the work you do to move the
handle • You can increase the work input by increasing
the input distance, the input force, or both
![Page 27: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/27.jpg)
• The force the oar on the water causes an equal and opposite reaction force to be exerted by the water on the oar – this reaction force propels the boat through the water
• The only way to increase the work work output is to increase the amount of work you put into the machine
![Page 28: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/28.jpg)
Mechanical Advantage and Efficiency
![Page 29: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/29.jpg)
Mechanical Advantage
• Mechanical advantage of a machine is the number of times that the machine increases an input force
![Page 30: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/30.jpg)
Actual Mechanical Advantage
• A loading ramp is a machine used to move heavy items into a truck– The longer the ramp, the less force is needed to
lift a refrigerator into the truck
![Page 31: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/31.jpg)
Actual Mechanical Advantage (AMA)
• AMA = output force • input force
![Page 32: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/32.jpg)
Actual Mechanical Advantage
– If the ramp has a rough surface it will have less mechanical advantage than a ramp with a smooth surface • It takes a greater force to overcome the friction
![Page 33: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/33.jpg)
Ideal Mechanical Advantage(IMA)
• Ideal mechanical advantage of a machine is the mechanical advantage in the absence of friction– Because friction is always present, the actual
mechanical advantage of a machine is always less than the ideal mechanical advantage
![Page 34: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/34.jpg)
Ideal Mechanical Advantage(IMA)
IMA = input distance output distance
![Page 35: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/35.jpg)
Ideal Mechanical Advantage(IMA)
• A woman drives her car up onto wheel ramps to perform some repairs. If she drives a distance of 1.8 meters along the ramp to raise the car 0.3 meter, what is the ideal mechanical advantage of the wheel ramps?
• IMA = input distance = 1.8 m = 6 output distance 0.3 m
![Page 36: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/36.jpg)
Efficiency
• Efficiency – the percentage of work input that becomes work output- usually expressed as a percentage
• The efficiency of ANY machine is always less than 100%
![Page 37: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/37.jpg)
Efficiency
Efficiency = work output x 100% work input
![Page 38: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/38.jpg)
Quiz Review
• What is the unit for force?• What is the unit for power?• What is the unit for distance/displacement?• What is the unit for time?• What is the unit for work?
![Page 39: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/39.jpg)
Quiz review
• You must exert a force of 4.5 newtons on a book to slide it across a table. If you do 2.7 Joules of work in the process, how far have you moved the book?
![Page 40: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/40.jpg)
Quiz Review
• A catcher picks up a baseball from the ground. If the unbalanced force on the ball is 7.25 x 10 -2 Joules of work is done to lift the ball, how far does the catcher lift the ball?
![Page 41: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/41.jpg)
Quiz Review
• A machine has a work output of 8 joules and requires 10 joules of work input to operate. What is the machine’s efficiency?
![Page 42: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/42.jpg)
Quiz review
• What is the output distance of a machine with an input distance of 3.0 cm and an ideal mechanical advantage of 12?
![Page 43: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/43.jpg)
Simple Machines
![Page 44: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/44.jpg)
6 Types of Simple Machines
• Lever• Wheel and axle• Inclined plane• Wedge• Screw• Pulley
![Page 45: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/45.jpg)
Simple machines
• Many mechanical devices are combinations of the six types of simple machines
![Page 46: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/46.jpg)
Lever
• Lever- a rigid bar that is free to move around a fixed point
- the fixed point is known as the fulcrum
![Page 47: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/47.jpg)
Lever
• There are 3 classes of levers based on the locations of – input force, – output force, – and the fulcrum
![Page 48: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/48.jpg)
Lever
• First Class lever– Fulcrum of a first class lever is always between the
input force and the output force – Mechanical advantage depends on location of the
fulcrum
![Page 49: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/49.jpg)
Lever• Second class lever- output force is between
the input force and the fulcrum• Input distance is larger than output distance ,
which means you need less force • The mechanical advantage of a second class
lever is always greater than 1
![Page 50: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/50.jpg)
Lever
• Third class lever – input force is between the fulcrum and the output force
• Input distance is smaller than output distance • Mechanical advantage is less than 1
![Page 51: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/51.jpg)
Levers
• Levers
• Paul Rabil
![Page 52: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/52.jpg)
Lever
![Page 53: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/53.jpg)
Wheel and Axle
• Wheel and axle is a simple machine that consists of two disks or cylinders, each with a different radius– The outer disk is the wheel and the inner disk is
the axle– The input force can be applied to the wheel or the
axle
![Page 54: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/54.jpg)
Wheel and Axle
• To calculate the mechanical advantage of the wheel and axle
• Can have a mechanical advantage less than or greater than 1
Mechanical advantage = radius of input radius of output
![Page 55: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/55.jpg)
Wheel and Axle
![Page 56: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/56.jpg)
Inclined Plane
• If the input distance is greater than the output distance, the input FORCE is DECREASED
![Page 57: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/57.jpg)
Inclined plane
• Inclined plane- a slanted surface along which a force moves an object to a different elevation
• The ideal mechanical advantage of an inclined plane is the distance along the inclined plane divided by its change in height
• IMA = distance of inclined plane change in height
Teacher demo
![Page 58: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/58.jpg)
Wedges and Screws
• Wedges- v-shaped object that has inclined planes on the sides sloped toward each other
• The sloping sides push the wood a small distance apart
• Mechanical advantage is greater than 1
![Page 59: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/59.jpg)
Wedges and Screws
• Screw- an inclined plane wrapped around a cylinder– Screw that have threads closer together have a
greater ideal mechanical advantage
![Page 60: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/60.jpg)
Pulleys
• Pulley is a simple machine that consists of a rope that fits into a groove in a wheel– Pulleys produce an output force that is different in
size, direction, or both from the input force
![Page 61: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/61.jpg)
Pulleys
• The ideal mechanical advantage (IMA) of a pulley system is equal to the number of rope sections supporting the load being lifted– Three types of pulleys• Fixed Pulley• Movable pulley• Pulley system
![Page 62: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/62.jpg)
Pulleys
• Fixed Pulley– Wheel attached in a fixed location – Changes direction of the exerted force– IMA is 1 because the rope will lift the load the
exact distance you pull the rope
![Page 63: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/63.jpg)
Pulleys
• Movable Pulley– Is attached to the object being moved – Reduce the input force
![Page 64: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/64.jpg)
Pulleys
• Pulley system– Mechanical advantage depends on how the
pulleys are arranged– Each segment of the rope exerts a force equal to
the force you exert on the rope– Pulleys
![Page 65: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/65.jpg)
Compound Machines
• Combination of two or more simple machines that operate together– The output force of one of the simple machines
becomes the input force for another– Ex: • Clocks• Bicycles
![Page 66: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/66.jpg)
Compound Machines
![Page 67: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/67.jpg)
Simple machines
• Bill Nye Simple MAchines
![Page 68: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/68.jpg)
Energy
![Page 69: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/69.jpg)
Energy
• Energy is the ability to do work – Energy is transferred by a force moving an object
over a specific distance– Sooooo– Work is a transfer of energy– Both are measured in Joules
![Page 70: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/70.jpg)
Types of Energy
• Kinetic energy–Energy of motion
• Potential energy–Energy of position, stored energy
![Page 71: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/71.jpg)
Kinetic Energy
• The kinetic energy (KE) of an object depends on its mass (in kg) and speed (velocity v in meters per second)
KE=½ mv2
if you double the mass, the KE is doubled
if you double the speed, the KE is quadroupled!
![Page 72: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/72.jpg)
Practice problem
• A 70 kg man is walking at a speed of 2.0 m/s. What is his kinetic energy?
• KE = ½ mv2 m= 70 kg v = 2.0 m/s• KE = ½(70 kg) (2.0 m/s)2
• KE = 140 J
![Page 73: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/73.jpg)
Potential Energy
• Potential energy is the energy with the potential to do work– Two common forms• Gravitational• Elastic
![Page 74: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/74.jpg)
Gravitational Potential Energy
• Potential energy that depends on an objects height is called gravitational potential energy
![Page 75: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/75.jpg)
Gravitational Potential Energy
• An object’s gravitational potential energy depends on its mass (m), height (h), and acceleration due to gravity (g)
• Potential Energy (PE) = mgh
![Page 76: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/76.jpg)
Elastic Potential Energy
• Potential Energy of an object that is stretched or compressed is known as elastic potential energy – Something is considered to be elastic if it springs
back to its original shape– Rubber band- energy you add is stored as
potential energy
![Page 77: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/77.jpg)
Forms of Energy
• Mechanical energy• Thermal energy• Chemical energy• Electrical energy• Electromagnetic energy• Nuclear energy
![Page 78: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/78.jpg)
Mechanical Energy
• Energy associated with motion
![Page 79: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/79.jpg)
Thermal Energy
• All particles of matter are in constant motion so they have kinetic energy
• The total of the potential and kinetic energy of all microscopic particles make up its thermal energy
![Page 80: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/80.jpg)
Thermal Energy
![Page 81: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/81.jpg)
Chemical Energy
• Energy stored in chemical bonds– When bonds are broken, energy is released that
can do work
![Page 82: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/82.jpg)
Chemical Energy
![Page 83: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/83.jpg)
Electrical Energy
• The energy associated with electrical charges– Electric charges can exert a forces that do work
![Page 84: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/84.jpg)
Electrical energy
![Page 85: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/85.jpg)
Electromagnetic Energy
• Form of energy that travels as a wave
![Page 86: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/86.jpg)
Nuclear Energy
• Energy stored in atomic nuclei is nuclear energy
![Page 87: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/87.jpg)
Nuclear Energy
![Page 88: Work, Power, and Energy Mrs Sedlock Principles of Chemistry and Physics](https://reader035.vdocuments.us/reader035/viewer/2022062803/56649f225503460f94c3a7d3/html5/thumbnails/88.jpg)
How a Nuclear Power Plant Produces Electricity