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madmike159
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Homework Statement
A ball is thrown vertically upwards from a roof of a building and it lands 3 seconds later on the ground 7 meters below the roof. Calculate:
a) the speed with which the ball was thrown upwards
b) the maximum height of the ball above the ground
c) the speed with which the ball hits the ground
Homework Equations
v = u + at
s = ut + (1/2)(a)(t^2)
s = vt - (1/2)(a)(t^2)
v^2 = u^2 + 2as
s = ((u + v)/2)t
The Attempt at a Solution
I was trying to help a friend with this problem. I have tried breaking it down to 3 sections, up, down to starting height and down to the ground; but there never seems to be enough information to solve anything. I can't tell if I am missing something obvious or something was left out of the question in the book.
Up
s = ? u = ? v = 0m/s a = -9.8m/s^2 t = ?
Down
s = ? u = 0 v = ? a = -9.8m/s^2 t = ?
To Ground
s = 7 u = ? v = ? a = -9.8m/s^2 t = ?