Question
Two objects, one with a mass of 2 kg moving at 10 m/s, and another with a mass of 5 kg moving towards it at 4 m/s, collide and stick together as they come to rest. Calculate the total momentum before and after the collision. Show all work using the method on the intropage for full credit. (Hint: use your alternative portfolio to help if needed)
Answers
GPT-5 mini
Take the direction of the 2 kg mass (10 m/s) as positive.
Compute momentum of each object before collision:
- p1 = m1 v1 = (2 kg)(10 m/s) = +20 kg·m/s
- p2 = m2 v2 = (5 kg)(−4 m/s) = −20 kg·m/s (negative because it moves toward the first object)
Total momentum before collision:
p_total_before = p1 + p2 = 20 + (−20) = 0 kg·m/s
After collision they stick together and come to rest, so v_final = 0 m/s. Total mass = 2 + 5 = 7 kg.
Total momentum after collision:
p_total_after = (m1 + m2) v_final = (7 kg)(0 m/s) = 0 kg·m/s
Thus p_total_before = p_total_after = 0 kg·m/s (momentum is conserved).
Compute momentum of each object before collision:
- p1 = m1 v1 = (2 kg)(10 m/s) = +20 kg·m/s
- p2 = m2 v2 = (5 kg)(−4 m/s) = −20 kg·m/s (negative because it moves toward the first object)
Total momentum before collision:
p_total_before = p1 + p2 = 20 + (−20) = 0 kg·m/s
After collision they stick together and come to rest, so v_final = 0 m/s. Total mass = 2 + 5 = 7 kg.
Total momentum after collision:
p_total_after = (m1 + m2) v_final = (7 kg)(0 m/s) = 0 kg·m/s
Thus p_total_before = p_total_after = 0 kg·m/s (momentum is conserved).