A 1.00-kg duck is flying overhead at 1.50 m/s when a hunter fires straight up.The 0.010 0-kg bullet is moving 100 m/s when it hits the duck and stays lodged in the duck's body.What is the speed of the duck and bullet immediately after the hit?
A)1.49 m/s
B)2.48 m/s
C)1.80 m/s
D)1.78 m/s

Question

Quizplus · Accepted Answer

Momentum is conserved, so the total momentum before the collision is equal to the total momentum after the collision. The momentum of the duck before the collision is 1.00 kg * 1.50 m/s = 1.50 kg m/s. The momentum of the bullet before the collision is 0.0100 kg * 100 m/s = 1.00 kg m/s. The total momentum before the collision is therefore 2.50 kg m/s. After the collision, the duck and bullet are moving together, so their combined mass is 1.01 kg. Their combined speed is therefore 2.50 kg m/s / 1.01 kg = 2.48 m/s.

A 100-Kg Duck Is Flying Overhead at 1