Answer:
v= 11.06 m/s
Explanation:
Given that
Mass of the student ,m = 80 kg
Height ,h= 12.5 m
Force done by friction ,W'=-5.1 x 10³ J
Lets take the sped of the student become v m/s at the bottom.
From work power energy
Work done by all forces = Change in the kinetic energy
Work done by Gravity + Work done by friction = ΔKE
Initially the speed of the student is zero
[tex]m g h + W' = \dfrac{1}{2}mv^2[/tex]
m v² =2 m g h + 2 W'
80 v² =2 x 80 x 10 x 12.5 - 2 x 5.1 x 10³
80 v² =9800
v= 11.06 m/s
