Explain what a scalar quantity is and what is meant by a vector quantity.
A ball is projected horizontally from point $P$ at the top of a cliff with speed $15\,\text{m s}^{-1}$, as shown in Fig. 2.1. The cliff is $25\,\text{m}$ high. The ball lands on the ground at point $Q$. Air resistance is negligible. Calculate the vertical velocity of the ball immediately before it strikes the ground at $Q$.
Show that the time taken for the ball to reach the ground is $2.3\,\text{s}$.
Calculate the magnitude of the ball’s displacement from $P$ to $Q$.
Explain why the distance travelled by the ball is not the same as the magnitude of the displacement of the ball.
Calculate the magnitude of the ball’s displacement from $P$ to $Q$.
Explain why the distance travelled by the ball is not the same as the magnitude of its displacement.