Aim
To investigate the affect of the weight of the cake case on the time of fall.
Plan
Apparatus
10 x cake cases
2 x metre rules (accurate to 0.1cm)
1 x stop clock (which measures to 1/100 s)
Prediction
The greater the mass, the shorter the time period for the fall. (I expect this to happen because a falling object converts GPE to KE. With a greater mass, you get more GPE than if you drop it from the same height with a smaller height. Hence more KE, so it falls more quickly, and so takes less time to fall.)
Planned Method
I will drop a number of cake cases from a height of 200 cm. Time how long it takes for the cake case to hit the ground (start the clock when it is dropped and stop it when it hits the ground). Repeat the experiment for each number of cake cases twice (3 experiments in total).
Results
*This was anomalous and was ignored when calculating the time taken.
Analysis
The graph shows that as the mass gets greater, the time of fall decreases. If the mass of the cake cases doubles, the time period doesn’t quite halve (but gets close). This is in agreement with my prediction, which stated that “The greater the mass, the shorter the time period”.
This happens because a falling object converts GPE to KE. With a greater mass, you get more GPE than if you dropped it from the same height with a smaller mass. Hence more KE, so it falls more quickly, and so takes less time to fall.)
Evaluation
The graph gives a smooth curve, with most of the points on or around it. This shows that the experiment worked well and the method does not need much improving. More accurate results would not significantly alter the outcome as it seemed to be quite accurate.
The one anomalous result was probably due to slow timekeeping. It was spotted and ignored in the average and the analysis. The results seem to be quite reliable and seem to support the conclusion that; as the total mass of the cake cases increases, the time taken for them to fall decreases. I believe there should be a direct link between these two variables and may be worthy of closer and more accurate investigation. To obtain more accurate results, light gates may be used to automatically start and stop any timers and also a more consistent way of dropping the cake cases may be used to improve the quality of the results.
