After observing the results, I can absolutely claim that the speed of the trolley was affected by the height of the ramp. This means that, the steeper the slope is, the faster the car moves down the ramp. It is obvious that this occurred because, of the increased steepness of the slope. This means that the height increased had to have affected the speed. As I said in my hypothesis, the height does affect the moving object, because the mass does not change the speed.

Conclusion:

After following all of the steps, and obtaining the results, I can without any doubt claim my hypothesis being correct, because according to my hypothesis, the speed would increase the more the car's height increase. This is because the slope is getting steeper, and the potential energy is increasing, causing the Kinetic energy also to increase, resulting with the speed increasing, and this is what I wrote in my hypothesis.

Evaluation:

Here I would absolutely state that, even though, the trolley went out of the ramp and stuff like that, I would definitely say that after taking the average speed, the speed probably became quite accurate, because if the trolley fell down from the ramp once or twice, it would probably become quite accurate anyway, because of the fact of that I'm taking the average.
Anyway, I believe that the fact that the trolley fell down once or twice from the ramp, wouldn't affect the results so much. I believe that the trolley fell down from the ramp because; Louis (Chang) by mistake, probably held the trolley a bit to the side, causing the trolley, falling down/out of the ramp.

Sources:

http://www.freestudentstuff.co.uk/GCSE_Physics_-_Force,Mass_and_Acceleration_Coursework.htm

http://www.essaybank.co.uk/free_coursework/706.html

Our science book "Physics" writen by Graham Dolan, Mike Duffy, & Adrian Percival.....
&
The notes we received from Mr Roberts.