physics1 notesnotes on basic physics forces, forms of energy, energy conversions, and energy...
DESCRIPTION
Notes on basic physics forces, forms of Energy, Energy conversions, Energy resources, and simple machines with video linksTRANSCRIPT
Physics 1EnergyPPT. by, Robin D. Seamon
MOTION
•Position: the location of an object
•Direction: N, S, E, W
•Speed: distance over time (tells how fast it moved)
EXAMPLE: the soccer ball moved 20m east.
Did it move 20m in 2 sec? OR
Did it move 20m in 2 min?
Which is the slower speed?
How do you measure motion?
•Stopwatch
•Divide: distance time
QUESTIONS:
1. What is the speed of the golf ball that moves 35 m in 5 sec?
2. Why is a compass a useful tool to describe motion?
3. How can motion be described?
FORCE & MOTION
•Force: a push or pull on an object
The amount of force you apply, determines how fast the object will move
If an object stops, speeds up, slows down, or changes direction, a force has been applied to it!
EXAMPLES: gravity, lift, thrust, friction
EXAMPLE: Forces on a Shark
Thrust
Lift
Drag : air/water resistance
Describe the force the weight lifter is exerting on the bar. Are the forces balanced or unbalanced?
PRACTICE LINK
PRACTICE Q’s
Hydraulic Lift simulation
Activity 1
Quiz 2
Energy & Machines
•Energy: the ability to do work (joules)(amt. of E to lift an apple 1m)
•Machine: something that replaces human effort
•Friction: the force that slows down or stops motion
•Gravity: the fore that pulls all objects on Earth toward the center of Earth (All objects have gravity; the larger the object, the stronger the gravitational pull)
•Potential Energy: stored up Energy; energy ready to be used
•Kinetic Energy: energy of motion; WORKING Energy mv2
2
M= mass kg; v= speed
FORMS of ENERGY:
•Thermal energy: energy from the rapid movement of molecules, causing heat- high temp to low temp-moves faster at high temp
•Mechanical energy: Energy of motion & position-stays the same unless transfers to another object
•Electrical energy: energy from moving electrons in atoms (negative charge around atoms)
•Gravitational potential energy: potential energy an object has if it falls
•Elastic Potential energy: potential energy of an object as it is forced to change shape, but has the ability to return to its normal shape.
•Chemical energy: energy from the interaction of molecules
•photosynthesis sugar forms by work of joining different atoms together in certain patterns: C6 H10 O2
•burning wood releases E as heat
•explosion rapid release of E
•Nuclear energy: energy that comes from changes in the nucleus of an atom
•Fission break apart (power plants)
•Fusion put together (sun)100,000,000°C: H joins to form He
•Light energy: energy from light; vibrations of electrically charged particles (NOTE: do not need air to transmit… can transmit through a vacuum as photons)
•Sound energy: energy from sound waves; objects vibrate, transmitting some of the kinetic E to air around it, air particles vibrate & transmit E to your ear… YOU HEAR!
SIR ISAAC NEWTON: (1643-1727) Mathematician & astronomer
NEWTON LINK BIOGRAPHY
•Newton’s 1st law of Motion: objects remain still or in motion until another force is applied to it (law of inertia)
•Newton’s 2nd law of Motion: acceleration happens when a force is acted on an object. The greater the mass of the object, the more force is needed to move it. (f=ma)
•Newton’s 3rd law of Motion: for every action, there is an equal and opposite reaction
•NEWTON LINK: explore the 3 laws
http://www.mrdowling.com/601-newton.html
ENERGY CONVERSIONS:(changing from one form to another)
Elastic potential Energy
Chemical energy of food you eat: atoms rearrange to make energy for you
Energy pyramid
Light E > chemical E > we eat it > to kinetic E as we move & live
ENERGY CONVERSION LABMake a list of 15-20 gadgets. Denote the source of E and
into what kind of E it converts
GADGET SOURCE DESTINATION
Alarm clock Electrical E Light & sound E
Battery Chemical E Electrical E
Light bulb Electrical E Light & thermal E
Blender Electrical E Kinetic & sound E
ENERGY CONVERSION LABMake a list of 15-20 gadgets. Denote the source of E and
into what kind of E it converts
ENERGY CONVERSION LABMake a list of 15-20 gadgets. Denote the source of E and
into what kind of E it converts
ENERGY CONVERSION LABMake a list of 15-20 gadgets. Denote the source of E and
into what kind of E it converts
ENERGY CONVERSION LABMake a list of 15-20 gadgets. Denote the source of E and
into what kind of E it converts
ENERGY CONVERSION LAB 2
Choose one daily activity that you do. Trace the Energy back as far as
you can go.Soccer ball moves (mechanical Energy) > Kicking a soccer ball (mechanical Energy) > muscles move forward (mechanical Energy) > Energy goes to my muscles from food I eat > (chemical Energy) > the bacon I ate has Energy from the plants the pig ate (chemical Energy) > the plant has Energy from the sun (photosynthesis/light Energy) > the sun gives off light Energy from nuclear fusion > nuclear fusion comes from the combining of hydrogen atoms to make helium…
All machines require energy to work. Which source makes the most sense for the job?
QUESTIONS:
1. What is needed to operate a machine?
2. What is a device that replaces human effort?
3. Why does a machine that lifts boxes off the ground need energy?
Unbalanced Forces & Motion•Balanced Forces: forces that have equal measure & are balanced; net force of zero
•Unbalanced Forces: forces in which one is greater (stronger) than the other, causing motion
No motionNo motion Object moves leftObject moves left
What affects Motion?
•Friction: a force that acts on an object to STOP the motion: ground, air, bumps
•Inertia: the tendency of an object to remain still or in motion unless acted on by a force
•Momentum: product of the mass and velocity of an object
MODELS:
• Design: imagining and creating a best way to solve a problem
1.What are the limits?
2.What materials make sense?
3. Is space a limit?
• Model: testing your design; replica; computer simulations
• Communicating: report your designs, drawings, & findings
Pulley: uses grooved wheels and a rope to raise, lower, or move a load
Simple Machine: a tool that makes work easier
Lever: a stiff bar that rests on a middle support, used to lift or move loads.
http://www.cool-science-projects.com/simple-machine-science-project.html
Wedge: has a slanted side that ends in a sharp edge. This tool concentrates the energy to that one edge/point
Wheel & axle: a wheel with a rod through its center that lifts or moves loads
http://www.msnucleus.org/membership/html/k-6/as/technology/2/images/gear.gif
Inclined plane: is a slanted surface that helps move an object up
Screw: an inclined plane that is wrapped around a pole; hold things together or lift things up
www.yourdictionary.com/screw
QUESTIONS:
1. The motion of any object can be describe by its position an how that position changes over __
2. What is a push or pull on an object called?
3. In order to work, what do all machines require?
4. What type of energy is used to move things?
5. During a tug of war, each team is pulling on the rope with equal forces in opposite directions. What is this an example of?
6. The force of friction acts in which direction?
7. After a design is found, the designer must test the design, evaluate the test, and then what?
8. A teeter-totter is an example of which kind of simple machine?
time
force
energy
mechanical energy
balanced forces
Opposite direction object is moving
Communicate it
leverBBC Forces QUIZ
Energy Efficiency:
Closed system: group of objects that only transfer E to each other. (not everything is a closed system)
*In Conversion of E, some ALWAYS gets converted to thermal E (not lost!)
Energy efficiency: comparison of the amount of E before conversion, with the amount after conversion
How can you make machines more Energy Efficient? (more useful)
•Oiling mechanical parts reduces friction & heat loss
•Aerodynamic shapes use less E to overcome friction
LAB: Energy Trace
Pick a daily activity & trace it back to its source of E
Energy Resources
•Fossil Fuels: resource from buried Carbon:burning coal, oil & natural gas
NON-RENEWABLE RESOURCE
-Steam-turbine-generator-electricity
•Nuclear Fuels: uses radioactive metals, uranium & plutonium in chemical reactions to produce heat> steam> energy
NON-RENEWABLE RESOURCE
•Solar Energy:
HEAT or ENERGY
•solar cells hold water or silicon, sun/light heats it (= hot water/spaces or electric charge from heated silicon molecule)
RENEWABLE RESOURCE
NOTES
•Water: (Hydroelectric Power) water rushes down through tubes inside the dam. The moving water drives electrical generators, which may be built inside the dam
RENEWABLE RESOURCE
•Wind Energy: using the wind to turn turbines for energy
RENEWABLE RESOURCE
•Geothermal Energy: using heat from inside the earth to warm water> steam> energy (radioactive decay of uranium= heat)
RENEWABLE RESOURCE
•Biomassorganic matter that’sburned to releaseEnergy
Burning wood; captured methane; municipal waste;agricultural residue
RENEWABLE RESOURCE
ELECTRICITY
Activities LINK QUIZ
LAB ENERGY PRO’s & CON’s
List the advantages & disadvantages of the following sources of Energy.
ENERGY TYPE ADVANTAGE DISADVANTAGE
Fossil fuels
nuclear
solar
water
Wind
Geothermal
Biomass
BBC Energy Links
HOW STUFF WORKS:
Telephone system
Wii
Radio
Helicopters
Toilets
Microwaves
LCD & Plasma tv
Light bulbs
Air & refrigeration
Electricity 1
Electricity 2
Water Treatment Plants
QUIZ