# physics investigation- stopping distance

Thomas Stirling 13jn

Candidate number: 2671

Physics Investigation

Introduction

In my investigation I intend to gather enough evidence and explanation to see if and how the mass of a ball will affect its stopping distance.

I will carry out a series of tests starting with changing the mass of the ball then changing height which it’s dropped from.

Predictions

I predict that the mass of a ball will most defiantly affect the distance it takes to stop because as the mass increases, the amount of friction with the surface will increase which will slow down the ball sooner.

I believe if the mass of the ball is doubled the friction with the surface it’s on will double and therefore half the distance taken to stop.

Equipment

For my investigation the equipment I will require is:

• A ramp and stand ( 1 metre long)
• Carpet (2 by 0.5 metres)
• 2 balls of different masses but same size  ( ball 1, 2.8g and ball 2, 44.9g)
• 2 metre rules

My setup

My setup is pretty simple I will use a ramp with a rule along it and some carpet for the balls to roll along I will then use another rule to measure the distance taken to stop.

When I first set up my equipment the balls where rolling around everywhere, to overcome this problem I decided to curl the carpet into a half bowl shape the balls then rolled smoothly down the ramp and along the carpet.

Procedure

Firstly I will drop the lighter ball 1, and measure its stopping distance and record this result; I will then drop the same ball another 4 times and record those results. I will average the 5 repeated results in order to gain a fair distance for the stopping distance of each ball. I will then repeat this with ball 2 and accumulate an average. All other variables for now will be kept the same (i.e. gradient of ramp, height dropped from)

Test 1

In my first test I will be testing ball 1 of radius 2 cm and mass of 2.8g, against ball 2 of radius 2 cm and mass of 44.9g. I will be dropping the ball from 30cm up the ramp with gradient of 24.4°, my results are:

Analysis

My first test supports my prediction that the mass of a ball does affect the distance that it takes to stop, although ball 2 is over 16 times heavier so I would have expected the stopping distance to be shorter.

Test 2

Again I will use ...