A mechanical launcher fires a small steel ball towards a target on a laboratory floor.
The centre of the target is at the same height as the initial launch position. The target is at a distance of 9.5 m9.5\text{ m}9.5 m from the launcher. The ball is launched with an initial velocity of 14 m s−114\text{ m s}^{-1}14 m s−1 at an angle of 25∘25^\circ25∘ to the horizontal.
Air resistance has a negligible effect on the motion of the ball.
Describe how the kinetic energy of the ball changes during its journey from when it is fired until it reaches its maximum height.
Show that the time taken for the ball to reach its maximum height is about 0.60 s0.60\text{ s}0.60 s.
The ball passes over and misses the target before hitting the floor. Calculate the horizontal distance, measured along the floor, by which the ball misses the target.
The ball is now fired horizontally at 14 m s−114\text{ m s}^{-1}14 m s−1 into the target at very close range.
The ball sticks to the target. The collision between the ball and the target is inelastic.
Explain what is meant by an inelastic collision.
The target is mounted on low-friction wheels. The target has a much larger mass than the mass of the ball.
Using ideas of momentum, explain the velocity of the target immediately after the ball sticks to it.
