A bullet of mass 8.80 x 10-3 kilogram, moving at 1250 m/s impacts a tree stump and penetrates 4.00 centimeter into the wood before coming to rest. (Take the direction of the bullet to be in the positive direction.)

(a) Suppose that the acceleration of the bullet is constant, determine the force (including direction) exerted by the wood on the bullet.

.....kN

(b) If the similar force acted on the bullet and it had the equal impact speed but half the mass, calculate how far would it penetrate into the wood?

......cm