Solve problems involving elastic collisions and inelastic collisions (including explosions) using ∑ 1 2 𝑚𝑣𝑏𝑒𝑓𝑜𝑟𝑒 2 = ∑ 1 2 𝑚𝑣𝑎𝑓𝑡𝑒𝑟 2.

Two trolleys collide on a low-friction track. The graph shows the kinetic energy of each trolley before and after the collision. What can be inferred about the nature of the collision?

Two trolleys collide on a horizontal track. Before collision, trolley P (mass 2.0 kg) moves at 3.0 m s⁻¹ and trolley Q (mass 1.5 kg) moves at –2.0 m s⁻¹. After collision, trolley P moves at 0.5 m s⁻¹. The collision is classified as

A railway maintenance vehicle of mass \(2{,}400\) kg is travelling at \(6.5\) m s\(^{-1}\) along a straight track when it collides with a stationary freight cart of mass \(1{,}800\) kg. After the collision, the two vehicles move together as a single combined unit. Calculate the speed of the combined unit immediately after the collision. Show your working.