A laboratory launcher fires a high-density foam ball towards a target cart resting on a horizontal track.
The top of the cart is at the same vertical level as the initial launch position of the ball. The centre of the cart is at a horizontal distance of 21.0 m21.0\text{ m}21.0 m from the launcher.
The ball is launched with an initial velocity of 18 m s−118\text{ m s}^{-1}18 m s−1 at an angle of 40∘40^\circ40∘ 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 1.2 s1.2\text{ s}1.2 s.
The ball passes over and misses the target cart before hitting the floor. Calculate the horizontal distance, measured along the floor, by which the ball misses the centre of the target cart.
The ball is now fired horizontally at 18 m s−118\text{ m s}^{-1}18 m s−1 directly into the target cart at very close range.
The ball sticks to the target cart. The collision between the ball and the cart is inelastic.
Explain what is meant by an inelastic collision.
The target cart is mounted on low-friction wheels. The cart has a much larger mass than the mass of the ball.
Using ideas of momentum, explain the velocity of the target cart immediately after the ball sticks to it.
