A 20-g bullet with an initial velocity of 3.0  104 cm/s penetrates 6.0 cm into a stationary wall. The average force exerted on the bullet by the wall in bringing it to rest is approximately
A) 1.5  104 N.
B) 2.3 103 N.
C) 9.8  10-3 N.
D) 2.0  102 N.
E) 4.7  10-2 N.

Question

Quizplus · Accepted Answer

The work-energy principle states that the work done by the force is equal to the change in kinetic energy. The initial kinetic energy is (1/2)mv^2, and the work done is force times distance. Solving for force gives approximately 1.5 x 10^4 N.

A 20-G Bullet with an Initial Velocity of 3