Ramps, friction and gravity

We have been talking about forces, and also about which shapes roll and which don't.

Today we had to guess which of the following objects would roll on the ramp and which wouldn't.

Spool, car, topper, cork on its end, paper clip, sphere.

We guessed the spool, car and sphere would roll. The others have no circular end (except for the cork which rolled when we put it on its side), and so would not roll.
Gravity helps pull the objects to the ground, and friction slows them down (as does bumping into lollipop sticks, as we discovered)

The car and the sphere rolled best.

We used lollipop sticks to measure how far each item rolled.

Here is the result.

After this we raised the ramp to see if this would make any difference to how far the object would travel. 

It really did.

Our ball travelled 3 sticks further with the higher ramp and the car rolled a further 6 sticks even further than the sphere.

We loved testing this!