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FEllen

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## Homework Statement

I am currently conducting an EEI in which I am looking at the effects of increased mass, surface area and air pressure on terminal velocity. In my experiment, I dropped a parachute of 0.36m^2 from a height of 3m with a mass of 0.01kg. My result was that it took 3.036 seconds to fall, giving an average velocity of 0.988 m/s. Assuming the object did not reach terminal velocity, and exprienced constant acceleration, the impact velocity should then be around 2m/s (double the average). However, the estimated terminal velocity of the object I calculated was 0.79m/s. This is even less than the average velocity - which should theoretically be impossible. This has happened with most my results! Anyone know what I could be doing wrong? Even taking error into account does not decrease impact velocity enough.

## Homework Equations

Drag formula:

F= 1/2*ρCAv^2

Where F is the drag force;

ρ is the air density;

C is the drag coefficient;

A is the area of the parachute;

And v is the velocity through the air

Thus making terminal velocity:

v=√(2W/ρCA)

## The Attempt at a Solution

Air density was estimated to be 1.171kg/m^3, and the drag coefficient of the parachute was 0.75.

v=√(2*9.81*0.01/(1.171*0.75*0.36))

v= 0.79m/s