How Much Force Stops a Pole Vaulter?

[sensesfail]

Homework Statement

a 58kg pole vaulter falls from rest from a height of 5.3m onto a foam rubber pad. the pole vaulter comes to rest 0.38 seconds after landing on the pad

Calculate the constant force exerted on the pole vaulter due to the collision. Answer in N

Homework Equations

d = Vi(t) + (1/2)(a)(t²)
Vf = Vi + (a)(t)

The Attempt at a Solution

d = Vi(t) + (1/2)(a)(t²)
5.3 = 0 + (1/2)(a)(.38²)
73.4 m/s² = a

Vf = Vi + (a)(t)
Vf = 0 + (73.4)(.38)
Vf = 27.89 m/s

 

[rl.bhat]

d = Vi(t) + (1/2)(a)(t²)
5.3 = 0 + (1/2)(a)(.38²)
73.4 m/s² = a This is wrong. You have to find the velocity with which he lands on the rubber pad. That is his initial vlocity. And his final velocity is zero..Time is given. Find the retardation and hence the force.