1.1. A stuntperson aims to perform a motorcycle jump over a row of buses.  

The take-off and landing ramps are both at the same height, and the take-off ramp is angled at 20° above the horizontal.  

Each bus is 2.55 m wide, and the heights of the buses are less than the heights of the take-off and landing ramps.  

The stuntperson and motorcycle are modelled as a single particle.

If the stuntperson leaves the end of the launch ramp with a speed of $18ms{}^{-1}$, work out the maximum number of buses the stuntperson can clear, assuming they land on the landing ramp.

1.2. If the stuntperson wishes to jump over 16 buses using the same ramp, find the speed with which they should leave the ramp, giving your answer to three significant figures.