Suppose that an object is dropped from a height of h meters and hits the ground with a velocity of v meters per second. Then =v19.6h. If an object hits the ground with a velocity of 27.7 meters per second, from what height was it dropped?

Question

Carry your intermediate computations to at least four decimal places, and round your answer to the nearest tenth.

Answer 1

(1/2) m v^2 =m g h
on earth g is about 9.8m/s^2
v^2 = 2 g h
v = sqrt (2 g h) = sqrt (2*9.8*h) = sqrt ( 19.6 h) ok so far
now
27.7 = sqrt (19.6 h)
27.7^2 = 19.6 h
767/19.6 = h