A 420-G Bullet Embeds Itself in a 20

Multiple Choice

A 4.20-g bullet embeds itself in a 20.0-kg block, which is attached to a horizontal spring with a force constant of 950 N/m. The maximum compression of the spring is 2.10 cm. What is the speed of the bullet just before it hits the block?

A) 690 m/s
B) 700 m/s
C) 672 m/s
D) 900 m/s
E) 952 m/s