Question

A boy standing on a bridge 150m above the canyon floor throws a stone downward with a speed of 20.0m/s.
A) with what velocity will it hit the ground?
B) How long will it take to descend?

Answer 1

Answer:

57.97m/s

12.1s

Explanation:

Use one of the key equations of accelerated motion and sub in the values

vf^2=vi^2+2aΔd

vf^2=(20)^2+(2*9.8)(150)

vf^2 = 3340

vf = 57.79m/s (square rooted both sides)

now use another equation

Δd = (vi+vf/2)Δt

and rearrange for Δt

Δt = (2Δd-vf)/vi

sub in values

Δt = (2*150-57.79)/20

Δt = 12.1s

mark me as brainliest if this helped!