Astronaut in rotating space station

[bon]

Homework Statement

cylindrical space station - large diameter, thin walled - radius r, mass M rotating in deep space, no gravity

1)radial spokes of negligible mass connect the cylinder ti the centre of motion. Astronaut mass m climbs a spoke to the centre. What is the fractional change in apparent gravity on the surface of the cylinder?

2)if the astronaut climbs halfway up a spoke and let's go, how far form the base of the spoke will he hit the cylinder? Assume the astronaut is point like..

Homework Equations

The Attempt at a Solution

1) Got the answer to be 1+m/M for ratio after/before..

is this right? I applied conservation of energy rather than angular momentum...why is angular momentum not conserved?

2) How do i do this one? Consv of energy again?

 

[bon]

anyone?

 

[bon]

Anyone able to help with this please? :)

 

[bon]

*bump*

 

[ehild]

You forgot to show your work again. :)

ehild

 

[bon]

Ok I didn't show because I'm just wanted to ask the following question first:

In the two cases, it is ENERGY rather than ANGULAR MOMENTUM that is conserved - yes? Why is angular momentum not conserved?

 

[bon]

any ideas?

 

[ehild]

The angular momentum of the whole space-station+ astronaut is conserved, as there is no external torque.

ehild