Physics CourseWork - Terminal Velocity

* The height the cake cases are dropped from

* The number of cake cases dropped (so effecting the weight)

* The angle at which the cake cases are dropped

* The air condition e.g. wind may effect the time

The one that I will be changing is the number of cake cases being dropped.

Fair Test:

I will make this a fair test by

• Dropping them all from the same height of 2 metres at the same angle

• Dropping each one 6 times and then finding the average

• Using the same size and type of cake cases each time

• Dropping them all inside the classroom where the air will be still

Prediction:

I think that as the number of cup cases increase, so the weight increases, the shorter time it will take before hitting the floor, the terminal velocity will be faster.

Terminal velocity is when the air resistance becomes equal to the gravity force and so acceleration stops, the object cannot go any faster it has reached terminal velocity.

At the instant of release there is no friction because the object is not moving. The weight of the object makes it accelerate downwards, because gravity is acting on it, the heavier the object the faster it will accelerate.

Because gravity is a constant force, it always stays the same; the velocity and the air resistance have to increase to balance it. So unless the weight of the paper case changes there is always the same force of gravity acting on it.

So it is expected that there will be a straight line of best fit on our graph of results.

Analysis:

The results gained from the experiment show that my prediction was correct, as the amount of Newtons increase the terminal velocity is faster, the shorter time it takes for it to hit the ground. So then the more paper cake cases that were dropped the faster its terminal velocity.

The graph produced a line of best fit as expected.

This is because as the weight was increasing the less time it was taking to reach the floor. A person was timing from the instant of release to the instant of impact with the floor. The shorter time means that there is less of a margin for human error, so the heavier the object the faster it falls and so it is more difficult for a person to time accurately. Less time between release and impact means that a human error matters more; 1 second is a higher percentage in 2 seconds than it is in 5 seconds.

At the instant of release there is no friction because the object is not moving. The weight of the object makes it accelerate downwards, because gravity is acting on it, the heavier the object the faster it will accelerate.

The results show that the terminal velocity increases steadily each time. 3.15m/s is the average increase in the terminal velocity each time another paper cake case is added. This shows that adding extra weight increases the terminal velocity quite significantly. This is because terminal velocity is when the air resistance becomes equal to the gravitational force acting on the object and so the acceleration stops. The heavier the object the shorter time it takes for it to reach its terminal velocity.

Evaluation:

I think the experiment worked quite well, a lot of reliable results were obtained which could be analysed easily and this meant we were able to fulfil our aim.

Most of the results are quite reliable; we did 6 experiments at each weight and took an average, which meant they were quite reliable. But because of human error they may not have been as reliable as they could have been, especially as the number of paper cases, and so the weight, increased.

We could have improved the experiment by using data logging, electronic sensors, to drop the paper cases through, this would have eliminated human error.