Two freight wagons, X and Y, are travelling towards each other on a straight, horizontal, friction-free railway track.
Wagon X has a mass of 2.20×104 kg2.20 \times 10^4\text{ kg}2.20×104 kg and is moving to the right at a speed of 3.50 m s−13.50\text{ m s}^{-1}3.50 m s−1.
Wagon Y has a mass of 1.40×104 kg1.40 \times 10^4\text{ kg}1.40×104 kg and is moving to the left at a speed of 2.30 m s−12.30\text{ m s}^{-1}2.30 m s−1.
The wagons are involved in an inelastic collision. They couple together upon impact and move as a single combined unit.
State the physical quantity that is conserved in an elastic collision but not conserved in an inelastic collision.
Show that the speed of the joined wagons immediately after the collision is approximately 1.24 m s−11.24\text{ m s}^{-1}1.24 m s−1.
Calculate the magnitude of the impulse that acts on each wagon during the collision. Give an appropriate unit for your answer.
Explain, without doing a calculation, how the motion of the wagons immediately after the collision would be different if the collision were perfectly elastic.
