Question

A student drops a ball from the top of a tall building; the ball takes 2.8 s to reach the ground.
1. what was the ball's speed just before hitting the ground?
2. What is the height of the building?

help please?

Answer 1

assuming it drops from rest you know:
vo=0
t=2.8
a=9.8 (gravity assuming down is +)
v=?
use the equation v=vot+at^2

then you want to find height.
x= vot+.5at^2

Answer 2

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