A vertical rod is hit at one end. What kind of wave propagates in the rod, if

(a) the hit is made vertically?

(b) the hit is made horizontally?

Consider the following statements about sound passing through a gas.

$\left(\mathrm{A}\right)$ The pressure of the gas at a point oscillates in time.

$\left(\mathrm{B}\right)$ The position of a small layer of the gas oscillates in time.

When we clap our hands, the sound produced is best described by (Here, $p$ denotes the change in pressure from the equilibrium value.)