Question Detail
Question
A 60 g parcel explodes, sending a 45 g piece to the left and another to the right with a velocity of 40 m/s. What is the velocity of the 45 g piece?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Initial momentum = 0. After explosion, let m1 = 45 g = 0.045 kg, m2 = 60 - 45 = 15 g = 0.015 kg. v2 = 40 m/s (to the right). Conservation of momentum: 0 = m1 v1 + m2 v2 => 0 = 0.045 v1 + 0.015 × 40 => 0.045 v1 = -0.6 => v1 = -0.6 / 0.045 = -13.33 m/s. So the 45 g piece moves left at 13.3 m/s.
Hint
Use conservation of momentum. The total momentum before explosion is zero.