Recent content by kaka2007

A 2.25-g bullet embeds itself in a 1.50-kg block, which is attached to a spring of force constant 785 N/m. If the maximum compression of the spring is 5.88cm find (a) the initial speed of the bullet and (b) the tie for the bullet-block system to come to rest I used: E = K + U =...

A charging elephant with mass 5230kg comes toward you with speed of 4.45m/s. You toss a 0.15 rubber ball at the elephant with a speed of 7.91 m/s. (a) When the ball bounces back toward you, what is the speed? Answer= 16.8 I don't know if the answer is written wrong in the back of the book...

Appreciate the help. I figured something was wrong w/ that side of the equation. So the general rotational equation is (I think) K = 1/2Iw^2. I assume I should replace w with v/r? Giving me K = 1/2Iv^2/r^2. The book gives me two moments of inertia for a disk. One is 1/2MR^2 but there is...

A 1.3kg block is tied to a string that is wrapped around the rim of a pulley of radius 7.2cm. The block is released from rest. (a) Assuming the pulley is a uniform disk with a mass of 0.31kg, find the speed of the block after is has fallen through a height of 0.5m. Answer = 3.0 m/s I can't...