Homework Help: Newton's laws question [grade 12]

1. Oct 4, 2009

bigmac

1. The problem statement, all variables and given/known data

A tree house has a vertical "fire pole" of smooth metal, designed for quick exits. A child of mass 35.7 kg slides down the pole with constant acceleration, starting from rest. The pole is 3.10m high. The journey to the ground takes 2.00s.

a) what is the magnitude of the downward acceleration of the child?
b) what is the magnitude of the upward force of friction exerted by the pole on the child?

2. Relevant equations

Fnet = ma

3. The attempt at a solution

This is what I got so far but I have no idea on how to solve this...any pointers?

Fg = 35.7 x 9.8 = 349.86N

Umm if its constant acceleration or velocity the Fnet is 0 right?

2. Oct 5, 2009

rl.bhat

Height of the pole is given. The time taken to slide on the pole is given. Using kinematic equation find the acceleration. Obviously it is not g, because it is not a free fall. It leads to find the frictional force.