9 is D I believe, I don't know about 10
Force is transferred from the moving ball to the stationary ball.
Ans:
C
Explanation:
because it is moving down the stairs
The normal stress follows the formula written below:
σ = F/A
There are two types of stress, axial and tangential. Since we are only given with the dimension of the radius (and not the length), the possible stress is axial. So, the area is,
A = πr² = π(0.75 in)² = 1.767 in²
So,
σ = F/A = 500 lb/1.767 in² = <em>282.94 psi</em>
B when is spins it means its rotating east and west directions
