# Homework Help: Glider pulled by suspended mass

1. Sep 30, 2011

### slapshot151

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

A 1.00-kg glider on a horizontal air track is pulled by a string at an angle θ . The taut
string runs over a pulley and is attached to a hanging object of mass 0.500 kg . (a) Show that the speed vx of the glider and the speed vy of the hanging object are related by vx = uvy, where u = z(z2–h02)–1/2. (b) The glider is released from rest. Show that at that instant the acceleration ax of the glider and the acceleration ay of the hanging object are related by ax = uay.

2. Relevant equations

vy2+h02=z2 (i think...)

3. The attempt at a solution

having problems with part b)
i tried to obtain vx=uvy by deriving the following equation by t:

vy2+h02=z2

see attachment for my attempt.

i've been working on this one problem for a few hours now... i dont get it

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2. Sep 30, 2011

### slapshot151

anybody?

3. Sep 30, 2011

### Staff: Mentor

Draw the triangle incorporating z, ho, and x. What is x in terms of the other variables?

When the hanging mass falls a given distance, what happens to the length of z? How does x change when z changes? How does a change in the length of z relate to the velocity of the falling mass?

Hint: Differentiation is required, and then an application of the chain rule.

4. Sep 30, 2011

### SammyS

Staff Emeritus
Last edited by a moderator: Apr 26, 2017