Apparatus
- String
- Pen (Marker)
- Cake Cases
- Meter ruler
- Stopwatch
Fair Test
Reaction time is a problem with the people timing the cake cases while they are falling, I will do the test three times to get an average and hopefully correct any errors. I will also use the same time keepers each time.
Wind and a draft is a problem, I will try to do the experiment away from any doors and windows.
Prediction
I think that if a paper cake case is heavier it will fall faster, this is because it will take longer for gravity and air resistance to even out, this means a heavier object will have a higher terminal velocity. If the paper cake holders were in a vacuum they would both fall at the same speed.
Detailed Theory
The SUVAT equation can be used to find out how long it should take for the cake cases to fall if there was no air resistance. The SUVAT equation does not take air resistance into the equation so it does not work well in a real life situation. We use the equation S=UT+½AT².
s = Distance = 4m
u = Initial Velocity = 0
v = Final Velocity = ?
a = Acceleration = 10m/s
t = Time Taken = ?
4 = 5 * T²
4/5 = T²
0.8 = T²
T = √0.8
T = 0.9 Seconds
It should take 0.9 seconds for any amount of cake cases to drop from 4 meters if there was no air resistance.
We will do the experiment and see how long it does take for the cases to fall.
By the second section the numbers aren’t changing very much so it has reached its terminal velocity. When we do our final experiment we will not measure each section instead we will measure the last two meters after it has dropped for two meters giving it plenty of time to reach final velocity.
Results
Conclusion
The more cases there were the faster they fell. This is because it will take longer for gravity and air resistance to even out; this means a heavier object will have a higher terminal velocity. If the paper cake holders were in a vacuum they would both fall at the same speed.
By Thomas Price 10.3/10E Mrs Strickland
