What Factors Affect the Motion of a Toy Car Down a Slope?

[phzy]

Homework Statement

hi, i am writing a report about the motion of toy car.
experiment has done using a toy car and a card board slope, the toy car was slide down the slope. change of angle of slope, change of mass of toy car, change of materials covered on the slope were tested, the time it takes to hit the ground was recorded. also tested using the first car strikes a second car down the slope, and the distance the second car traveled is recorded.
It is a high school level report. Just wondering what area should i research and investigate? I have calculated the PE,KE,velocity under different situations. Thank you very much!

Homework Equations

The Attempt at a Solution

 

[Simon Bridge]

The general field would be "kinematics".
You should also look into "conservation of energy" and "conservation of momentum" and, considering the different surfaces ... maybe, friction.

The toy car is on wheels?
All you really need to do for the report is write about what you discovered.
eg. How did the angle of the slope affect the travel time? How did the surface type affect the travel time?

hmmm ... so you didn't send the car down one slope and up a second one at a different angle, and compare the height reached up the second slope with the height started from the first?

 

[phzy]

thank you for your reply, Simon. i didn't use the second slope. the attached files are my actual report, could anyone have a look for me? and give me some more advice please? Thank you so much!

 

[phzy]

sorry i cannot upload the word file since it's larger than 300kb...
below is my discussion. please have a look of it and give me some advices! thank you!

Discussion
Change of angle
30°

The height of the slope is:
sin30°*0.47=0.235 Metres
PE=0.019464*9.8*0.235
PE=0.0448J
KE=PE=1/2 〖mv〗^2
v=2.146 m/s
The average time for the toy car to hit the ground of 5 attempts is 0.484 sec
The length of the slope is 0.47m
speed=d/t
speed=0.971 m/s


45°

The height of the slope is:
sin45°*0.47=0.332 Metres
PE=mgh
PE=0.0633J
PE=KE=1/2 〖mv〗^2
v=2.551 m/s
The average time for the toy car to hit the ground of 5 attempts is 0.356 sec
The length of the slope is 0.47m
speed=d/t
speed=1.3202 m/s



60°

The height of the slope is:
sin60°*0.47=0.407 Metres
PE=mgh
PE=0.0776J
KE=PE=1/2 〖mv〗^2
v=2.824 m/s
The average time for the toy car to hit the ground of 5 attempts is 0.294 sec
The length of the slope is 0.47m
speed=d/t
speed=1.5986 m/s
Angles 30° 45° 60°
Velocity (m/s) 2.146 2.551 2.824
Speed (m/s) 0.971 1.3202 1.5986
Potential energy (J) 0.0448 0.0633 0.0776
The above table shows the velocity and speed of the toy car sliding from different angle of slopes. It indicates that as the angle of slope increased, which increase the height of starting point of the car, the velocity, speed and potential energy and kinetic energy of the toy car increased too.

Force on the slope

30°
mgsinθ=0.019464*9.8*sin30°=0.09537N
mgcosθ=0.019464*9.8*cos30°=0.1651919209N
mg=0.1907472
45°
mgsinθ=0.019464*9.8*sin45°=0.1348786386
mgcosθ=0.019464*9.8*cos45°=0.1348786386
mg=0.1907472
60°
mgsinθ=0.019464*9.8*sin60°=0.1651919209
mgcosθ=0.019464*9.8*cos45°=0.0953736
mg=0.1907472




Change of materials

Paper
According to the result recorded, the toy car takes 0.484 seconds to hit the ground when the surface of slope is made of paper.
speed=d/t
speed=0.9711m/s
Polyester fibre
According to the result recorded, the toy car takes 0.434 seconds to hit the ground when the surface of slope is made of polyester fibre.
speed=d/t
speed=1.0829m/s
Plastic
According to the result recorded, the toy car takes 0.454 seconds to hit the ground when the surface of slope is made of plastic.
speed=d/t
speed=1.0352m/s


Fabric
According to the result recorded, the toy car takes 0.422 seconds to hit the ground when the surface of slope is made of fabric.
speed=d/t
speed=1.1137m/s
Materials Paper Polyester fibre Plastic Fabric
Speed (m/s) 0.9711 1.0829 1.0352 1.1137
The table above shows the speed of the toy car sliding down a 30° slope covered by different materials. On a slope that covered by fabric, the toy has the highest speed, which indicates that fabric has the least friction against the plastic made wheels of the toy car.
Change of mass and momentum

Momentum before the collision with car 2
No mass
P=0.019464*2.146=0.0418 kg∙m/s
50g
P=(0.019464+0.05)*2.146=0.1491kg∙m/s
100g
P=(0.019464+0.1)*2.146=2.1878kg∙m/s

200g
P=(0.019464+0.2)*2.146=0.4710kg∙m/s

 

[Simon Bridge]

sorry i cannot upload the word file since it's larger than 300kb...

Won't look at word files anyway :( maybe one of the others will.
It's bad netiquette to provide data in restricted proprietary formats... though some are worse than others.

below is my discussion. please have a look of it and give me some advices! thank you!

That's not a discussion. It's a list of observations and calculations.
Advise: talk about what you learned from them.

Want to summarize your conclusions?

It's a shame you didn't use the second ramp - it leads to one of the most important results in physics.

 

[CWatters]

In the first part you say momentum "refers to the quantity of motion that an object has". That's not a very good definition. Check wikipedia or similar for a better one?

Could also do with some more words to describe the "forces acting on an object on a slope".

Also formatting (eg sub headings).

Perhaps also more words on what you set out to achieve? Were you aiming to calculate the coefficient of friction for a car rolling on different materials?

In the results section... Perhaps plot some graphs? Time vs angle? What do the results actually mean? (Friction is lower on material X? Friction is only significant for angles less then Y?) It needs some discussion of the results and a conclusion. Did you achieve what you set out to achieve? Were any results surprising or unexpected?

 

[phzy]

Thank you very much for your help ! Simon Bridge, Cwatters