Physics momentum

Question

A 2000 kg car traveling at 20 m's collides with a 1000 kg car at rest at a stop sign. If

the 2000 kg car has a velocity of 6.67 m/s after collision, find the velocity of the 1000

kg car after the collision.

Answer 1

Total initial momentum (P_i) before collision:

p_1i (initial momentum of car 1): 2,000kg*20m/s = 40,000kg*m/s

p_2i (initial momentum of car 2): 1,000kg*0 = 0

Total final momentum (P_f) after collision will still be 40,000kg*m/s

P_f = 40,000 = p_1f + p_2f

p_1f = 2,000kg*6.67m/s = 13,340

Therefore:

p_2f = 40,000 - 13,340 = 26,660 = 1000*v_f

v_f = 26.66 m/s