First of all we set the ramp to a particular height measured from the floor with a metre stick.
Then we let the trolley roll down the ramp into the box.
The trolley was stopped by friction between the box and the floor. We measured how far the box slid. We found that the higher the ramp, the faster the trolley and the further the box slid. It's like the braking distance for a car which is also due to friction.
Then we taped a 1kg mass to the trolley. It slid further each time.
When we repeated with 2kg, it went even further. Heavy vehicles and fast vehicles have bigger braking distance.
