Use energy methods to solve this problem. A $20\mathrm{.}0$ kg cannonball is fired at $15\mathrm{.}0\frac{m}{s}$ directed at an angle of $30$ above the horizontal from the top of a $10\mathrm{.}0$ m tall cliff. Air resistance can be ignored $($not a good idea if you are firing a cannon in real life!$)$

a$.$ Determine the highest point of the cannonball as measured from the base of the cliff.

b$.$ Determine the speed of the cannonball when it reaches the ground below the cliff.