Compute all parts of following question:
Question: A rifle with a barrel length of 65cm fires a 10g bullet with a horizontal speed of 400m/s. The bullet strikes a block of wood and penetrates to a depth of 15cm.
Part I: What resistive force (assumed to be constant) does the wood exert on the bullet?
Part II: How long does it take the bullet to come to rest after entering the wood?
I need help to find how long it takes the bullet to come to rest after entering the wood.