A22.3-g bullet moving at 1 000 m/s is fired through a one-kg block of wood emerging at a speed of 100 m/s. what is the change in the kinetic energy of the bullet-block system as a result of the collision assuming the block is free to move?

-10837 J

Explanation:

The law of conservation of momentum states that the initial total momentum is equal to the final total momentum, so:

where

m = 22.3 g = 0.0223 kg is the mass of the bullet

is the initial velocity of the bullet

M = 1 kg is the mass of the block

is the initial velocity of the block

is the final velocity of the bullet

is the final velocity of the block

Solving for we find

The total kinetic energy before the collision is:

And the total kinetic energy after the collision is:

So, the change in kinetic energy is

f=ma newton's second law 7x8=56n

iron would move it is magnetic there is a mag field around the current in the wire