Question

6.
A physics book of unknown mass is
dropped 4.50 m. What speed does the
book have just before it hits the
ground?

Answer 1

Answer:

Explanation:

Givens

vi = 0

a = 9.81

d = 4.50 m

vf = ?

Formula

vf^2 = vi^2 + 2 * a * d

Solution

Substitute the knowns into the formula

vf^2 =0 +  2 * 9.81 * 4.50

vf^2 = 88.29                          Take the square root of both sides.

sqrt(vf^2) = sqrt(88.29)    

vf = 9.40 m/s