physics - speed chapter explained in a easy way for children
Post on 12-Apr-2017
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SPEED IT's unimaginable power
Speed
Speed
Have you ever run ?
Speed If you had after a few moments after finish of this race
the times of the you and the other runners flash up on a scoreboard. If the race was over 100 metres, or any other distance, you may think that a runner ran the entire distance could be worked out using the time. However you would be wrong.
SpeedThe runners were stationary when the starter
gun was fired so they began to run increasingly faster, or accelerate, to get moving.
The may have run steadily for the most of the race and then accelerated as much as they could for the final sprint to the finish.
Speed is a measure of the distance covered by an object in a certain time.
Speed records
People trying to beat the land speed record must drive their vehicle at full
speed between two markers.
Green monsterArt arfan drove itGreen Monster
Spirit of AmericaSpirit of America Craig Breedlove drove it
The Blue FlameThe Blue Flame
Gary Gabelich drove it
Thrust 2Thrust 2
Richard Noble drove it
Thrust SSCThrust SSC
Andy green drove it
Measuring speed – The speedometer
The speedometer in a vechile is connected by a cable to a shaft which turns the wheels. There is a wire in the cable which is connected to the shaft by gear wheels. When the shaft turns, the wire in the cable turns too. At the other end of the wire is a magnet. It spins round when the vehicle's wheel turn.
The magnet is surrounded by a circular metal cap which is affected by the magnetic field generated by the spinning magnet. The cup is made to turn, the turning effect increasing as the speed of the spinning magnet (and the moving vehicle ) increases. The cup is connected to a spring and a pointer. The spring prevents the cup spinning but also allows it to turn further as the vehicle's speed increases. The pointer turns with the cup and moves across the scale of the speedometer dial.
Do you know who found speedometer ?
Charles Babbage is credited with creating an early type of a speedometer, which were usually fitted to locomotives.
The electric speedometer was invented by the Croatian Josip Belušić in 1888, and was originally called a velocimeter.
A cyclocomputer or cyclometer is a device mounted on a bicycle that calculates and displays trip information, similar to the instruments in the dashboard of a car. The computer with display, or head unit, usually is attached to the handlebar for
easy viewing.
In simple words it is a bicycle informatory ( speed, pace ,distance ,etc..)
CyclometerThe computer or monitor. Cyclocomputer sensor
Sensor
Inventor of Cyclocomputer
In 1895, Veeder invented the Cyclometer. The Cyclometer was a simple mechanical device that counted the number of rotations of a bicycle wheel.
Stopwatch
What is a stopwatch ?
A stop watch is a handheld timepiece designed to measure the amount of time elapsed from a particular time when it is activated to the time when the piece is deactivated. A large digital version of a
stopwatch designed for viewing at a distance, as in a sports stadium, is called a
stopclock.
Samuel Watson (fl. c.1687-c.1710), was a horologist (clock and watch maker) who invented the 5 minute repeater, made the first stopwatch. He made a clock for King Charles II and was an associate of Isaac Newton.
Founder of Stopwatch
What do you understand by the
term speed trap gun ?
A radar speed gun (also radar gun and speed trap gun) is a device used to measure the speed of moving objects. It is used in law-enforcement to measure the
speed of moving vehicles and is often used in professional sports, for such things as the
measurement of the speed of pitched baseballs, runners and tennis serves or speed a vehicle travels.
Speed trap gun
The radar speed gun was invented by John L. Barker Sr., who developed radar for the military during World War II.
Light gatesThey detect when something goes through them and how long
it takes to cross.The light gate has a beam going from one LED/IR light source
onto a detector. As something goes through it, the beam is "Cut".
The light gate measure how long the beam has been cut for. That gives you a measure for time.
Some light gates will allow you to plug in the length of the crossing object, and then it'd automatically calculate:
Length of object/time = How fast it was traveling
Light GatesErwin Sick invented his light
gates in 1950 .
For extra information about Erwin Sick and his inventions :
http://www.sick.com/us/en-us/home/about_us/about_sick/Pages/historyofsick.aspx
Why do we use distance / time
graph ?
A distance time graph is a visual representation of collected data. The graph has a horizontal x axis which represents time and a vertical y axis that represents the distance. When the
line on the graph is horizontal, then it implies that an object is stationary and when it is straight, but sloped then the object is
moving at a steady speed.
In the previous image you saw the term 'Velocity '
What means velocity in your words ?
Velocity is the rate of change of the position of an object, equivalent to a specification of its speed and direction of motion. Example
60 km/h to the north. Velocity is an important concept in kinematics, the branch of classical mechanics which describes the
motion of bodies.
1. Scalar is the measurement of a medium strictly in magnitude.
2 . Vector Quantity is a measurement that refers to both the
magnitude of the medium as well as the direction of the movement the medium has taken.
Examples of scalar quantity :
Time - Scalar quantities often refer to time; the measurement of years, months, weeks, days, hours, minutes, seconds, and even
milliseconds.
Volume - Scalar quantity can refer to the
volume of the medium, as in how much of the medium is present. Everything from tons
to ounces to grams, milliliters and micrograms are all scalar quantities, as long
as they are applied to the medium being measured and not the movement of the
medium.
Speed and temperature - Two more commonly used scalar quantities in physical calculations are speed
and temperature. As long as they are not associated with a directional movement, they remain scalar
quantities. For instance, the measurement of speed in miles or kilometers-per-hour or the measurement of the temperature of the medium both remain scalar
quantities as long as they aren’t associated with the direction of the medium’s travel.
Examples of vector quantity :
Vector quantities, however, refer to both the direction of the medium’s
movement as well as the measurement of the scalar quantity.
Increase/Decrease in Temperature - The measurement of the medium’s temperature is a scalar quantity; the measurement of the increase or decrease in the medium’s temperature is a
vector quantity.
Velocity - The measurement of the rate at which an object changes position is a vector quantity. For example:
If a person quickly moves one step forward and then one step backward there would certainly be a lot of activity; but,
there would be "zero velocity."
A beginning reference point for the directional measurement in order to provide the directional element of the vector
quantity. Your beginning point could be centered in a north, south, east and west quadrant so thats the vector quantity can be applied to the medium’s movement. For example:
To describe a car's velocity you would have to state it as 70 miles per hour, south.
Another directional element that may be applied to the vector quantity is the different between vertical and horizontal
movements.
Velocity - The measurement of the rate at which an object changes position is a vector quantity. For example:
If a person quickly moves one step forward and then one step backward there would certainly be a lot of activity; but,
there would be "zero velocity."
In order to measure the vector quantity of the medium, there must be:
A directional measurement applied to the scalar quantity. For example:
Regardless of how fast an object is going, the direction of the movement must be described in the velocity vector such
as "rightwards" or "forward."
Thank You
Done by :
Deraj.R.MVI-C
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