I think that the speed of the cart will decrease as more weight is added on top of the cart. This is because the more weight that is placed on the moving vehicle/object, the more downward force is produced. This would increase the friction between the wheels of the cart and the ramp’s surface. The increase in friction would slow down the moving object (cart).
Apparatus
Trolley/cart- this is essentially a wooden block with wheels and a rubber end, to provide the collision with a cushion upon impact.
Weights- these were added to the trolley every turn. This was the independent variable and it was the only variable we had chosen to change.
Ramp- this is the means in which we are going to create the initial movement and cause the trolley to move.
Stopwatch- this is how we will measure the dependant variable (time).
Method Firstly we prepared our equipment for the first ‘run’. This involved fixating the ramp to a stable height. We also had to ensure that there were minimal blemishes/bumps on the ramp. We also checked to see that the timer was working and that we knew how to start and stop it. We then proceeded to let the trolley ‘roll’ down the ramp with no weights on top. We then repeated this 3 times (to provide us with a fairer, more realistic time). We then recorded the times in a table. We then repeated step 2, except we added a ** gram weight on top. This was attached by a elastic band. We tried to keep all of the variable constant, apart from the independent variable that we were measuring (weight). Step 2 was then repeated, changing the weight every time. We collected the data in a table.
Variables These are the variables that are controlled.
Controlled variables: - 1 metre distance Observer Trolley Angle of the incline
Independent variable: - Mass added to the trolley (g)
Dependent variable: - Velocity of trolley (m/s) Momentum of trolley (kg m/s)
Results
Mass (kg) Distance (m) Time (seconds) Velocity