A 1200-kg car moving at $15.6 \mathrm {~m} / \mathrm { s }$ suddenly collides with a stationary car of mass $1500 \mathrm {~kg} \text {. }$ If the two vehicles lock together, what is their combined velocity immediately after the collision?
A) 6.9 m/s
B) 8.6 m/s
C) 12.1 m/s
D) 5.5 m/s

Question

Quizplus · Accepted Answer

Using the conservation of momentum: $ (1200 \, \text{kg} \times 15.6 \, \text{m/s}) + (1500 \, \text{kg} \times 0 \, \text{m/s}) = (1200 \, \text{kg} + 1500 \, \text{kg}) \times v $. Solving for $ v $ gives $ v = 6.9 \, \text{m/s} $.

A 1200-Kg Car Moving At 15.6 m/s15.6 \mathrm {~m} / \mathrm { s }15.6 m/s

A 1200-Kg Car Moving At $15.6 \mathrm {~m} / \mathrm { s }$