If the upward movement starts from rest, what is the person's speed at this point?

Question

A person doing a chin-up weighs 770 N, disregarding the weight of the arms. During the first 24.0 cm of the lift, each arm exerts an upward force of 386 N on the torso.

Answer 1

Newton's Second Law is F = ma

( 2 ) ( 386 ) - 770 = m a = ( 770 N / g ) a

Solve for the acceleration a.

Then 2 a d = v²

Plug in the distance and the acceleration you just got and solve for the velocity v.

Answer 2

Total upward force of the hands = 386x2=772 N

Now lets calculate the acceleration

F=ma
Driving force - weight = ma
772 - 770 = (770/9.8) a
a=0.02545454545 m/s²


V²=2as+U²
U is initial speed which is zero
a is the acceleration
s is the distance

V²=2(0.02545454545)(0.24)
V=0.1105358848 m/s