Year 10 Cup cake cases experiment

Take one cup cake case and hold it up as high as you can. Time it as it falls to the ground. Do this 3 times to check that the result is REPEATABLE. It should fall at roughly a steady speed because it has a small weight (pull of gravity) and a large surface area so it is easy for the air resistance (drag) to become so large that it is the same size but opposite direction to the weight. When this happens, the resultant force is zero and there is no acceleration so it falls at a steady speed called the TERMINAL VELOCITY.

 Now put a second cup cake case inside the first. Hold it up as high as you can and drop it, timing the fall. The weight has doubled but the area is still the same so the only way the air resistance can double to achieve zero resultant force and terminal velocity is by going much faster.

 Keep adding cup cake cases, stacked inside each other to increase the weight whilst keeping the area the same.

Here is my graph. Notice the small random errors shown by points not quite on the best fit line. This is our third falling forces experiment and the pattern is still the same on the graph. It is further evidence that the theory of weight, air resistance and terminal velocity is true. The findings of the first experiment have turned out to be REPRODUCIBLE - same independent variable, same dependent variable, same control variable but different situation and yet STILL THE SAME PATTERN.