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What distance?

A can of tuna is dropped from a building. If the can takes 3.2 seconds to strike the ground, what distance did it fall?

d = (1/2)gt^2 = 4.9*3.2^2 = 50.2 m <==Answer
When solving any problem of this type it is helpful to use the following problem solving steps.

1) Write down what is known. *important*

Vi (initial velocity) = 0
t (time) = 3.2s
d = variable we are solving for
a (acceleration) = 9.8 m/s2

2) Which equation applies?
The correct formula will contain the known variables and only one unknown, which will be the variable we are solving for (d).

The correct formula is d = vi*t+1/2 at2 because vi=0, which makes the v0*t term drop out, leaving us with d=1/2at2

3) Now for the easy part, plug in and solve.
d = 1/2*9.8*3.22

The equation for this is d=(gt2)/2.
d= Distance
g= Gravitation Acceleration (which for earth is 9.807m/s/s)
t = Time

Then
d=(9.807*3.22)/2

Then it simplifies to:
d=50.210048
Hey Sun -- 3.2s freefall gives Vf of 32m/s ... ave speed of 16m/s runs 3.2s