1. An aeroplane wishes to travel due cast. A wind is blowing
south east at a speed of 40 m s-'. The speed of the aeroplane
relative to the air is 110 ms-,
(a) Find the direction in which the aeroplane should head.
(b) Find the resultant specd of the aeroplane.

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f