# The normal force exerted on a small sphere

1. Nov 19, 2010

### thedaydreamer

1. The problem statement, all variables and given/known data
A small sphere A of radius r and mass m rolls without slipping inside a large hemispherical bowl of radius R. The sphere A starts from rest at the top point on the rim of the hemisphere. Find the normal force exerted by small sphere when it touches the bottom of the hemisphere.

2. The attempt at a solution I'm unsure of how to approach this problem. I tried to use Conservation of Energy to find the velocity of the sphere but I dunno how that will help. I tried to use the fact that the relative acceleration to the inner surface of the bowl at the point of contact=0. This way I can find the frictional force but not the maximum normal force.

2. Nov 19, 2010

### tiny-tim

hi thedaydreamer!
yes, use conservation of energy (including rotational energy) to find the speed, then use Ftotal = ma to find N, where a is the https://www.physicsforums.com/library.php?do=view_item&itemid=27"

Last edited by a moderator: Apr 25, 2017
3. Nov 19, 2010

### thedaydreamer

Thank you tiny-tim. I should've noticed that myself. :)