An 80-G Bullet Is Suddenly Shot into a 4 $2500 \mathrm {~N} / \mathrm { m }$

Multiple Choice

An 8.0-g bullet is suddenly shot into a 4.0-kg block that is at rest on a frictionless horizontal surface, as shown in the figure. The bullet remains lodged in the block. The block then moves against a spring and compresses it by 3.7 cm. The force constant (spring constant) of the spring is $2500 \mathrm {~N} / \mathrm { m }$ What was the initial speed v of the bullet?

A) 460 m/s
B) 440 m/s
C) 480 m/s
D) 500 m/s
E) 520 m/s