Introduction
Speed is the rate at which something moves.Speed is a scalar quantity.It is defined by the equation v=d / t where:
v=speed of the object in meters a second or kilometers per hour.
t=the given time in which the object moved in seconds or hours .
d=the distance the object travelled in meters or kilometers.
In my experiment I let the moving object come to a stop at its own time, however today peoople do not use this method to come to a stop
they use devices called brakes. Brakes work by creating friction in the moving object. Brake shoes sre put on either side of a spinning or moving object
when they press against this object they cause friction thus taking energy away from the moving object until it stops.
Purpose: To determine the relation between speed and stopping distance of
a moving object
Hypothesis: My hypothesis is that the toy car having a greater speed will increase the stopping
distance of the car. I believe this because i think that the more speed the car has the more kinetic energy the car will have. The more energy the car
has the longer it will take the car to lose this energy and come to a stop, therefore giving the car a longer traveling time to accumulate a greater distance also the cars greater speed will let it travel a longer distance in a smaller amount of time.
Materials: The materials needed for this experiment are:
A Toy Car
A Ramp
A Long Area Which To Release The Car
A Measuring Tape
Procedure:
1.)Place the ramp in the long area at the desired height.
2.)Set up the car on the top of the ramp, make sure the car is straight so that when you release the car it will travel the straightest path possible.
3.)Release the car and measure how far the car travelled. Do this twice to ensure accurate results
4.)Then to determine the velocity of the car use the law of conservation of mechanical energy. Eg=mgh at the top of the ramp
=Ek=1/2mv(squared)at the level ground. For this equation you do not need to know the mass of the car.
Analysis:
Equations:(sorry sir i couldn't find a way to put the squared sign in you'll have to use your imagination.) height of ramp:16 cm stopping dis. :1.8 meters
At top of
ramp At level ground
Eg=mgh Ek=1/2mv
Eg=m(9.8 n/kg)(0.16m)
Eg=m1.6
m1.6=1/2mv
the m's cancel
1.6=1/2v
3.2=v
1.8m/s=v
height of ramp=25cm stopping dis.=2.25m
At
the top of
ramp At level ground
Eg=mgh Ek=1/2mv
Eg=m(9.8 n/kg)(0.25m)
Eg=m2.45
m2.45=1/2mv
the m's cancel
2.45=1/2v
4.9=v
2.2m/s=v
Height of ramp=35cm
Stopping Dis.=2.95m
At
top of
ramp At level ground
Eg=mgh Ek=1/2mv
Eg=m(9.8n/kg)(0.35)
Eg=m3.43
m3.43=1/2mv
the m's cancel
3.43=1/2v
6.86=v
2.6m/s=v
Height of ramp=45cm
stoppping Dis.=3.4m
At top
of
ramp At level ground
Eg=mgh Ek=1/2mv
Eg=m(9.8n/kg)(0.45)
Eg=m4.41
m4.41=1/2mv
the m's cancel
4.41=1/2v
8.82=v
3.0m/s=v
Height of Ramp
Stopping Distance
Speed
16 cm
1.8 meters
1.8 m/s
25 cm
2.25 meters
2.2 m/s
35 cm
2.95 meters
2.6 m/s
45 cm
3.4 meters
3.0 m/s
Conclusion:
After performing this experiment I have determined that my Hypothesis was correct the car's stopping distance did increase with the cars greater speed.
The reason for this is that the car had more potential energy due to the height of the ramp when this was changed into kinetic energy the car had a greater speed the result of more energy and a greater speed gave the car a longer distance since the car
had much more energy to use up before it came to a stop as compared to the energy of the car at a lower height. The car at a lower distance would have less potienal energy as a result of the smaller height and would thus have less kinetic energy as it moved down the ramp
causing it to use up the energy and speed it had in a lower amount of time.