A projectile is launched at speed u and angle 0 (as measured from the horizontal) outwards from the top of a high cliff. (a) Sketch the trajectory of the projectile for launch angles 0=5, 45 and 85. Use r(t) for the horizontal displacement from the launch point and y(t) for the vertical displacement from the launch point. (b) Using separate axes, now sketch the absolute distance, r(t) = r(t) + y(t), from its launch point as a function of time for all of the three launch angles above. (c) Obtain an expression for r(t). For which angles does r(t) have a stationary point? (d) For angles below these, what happens to r(t) as time increases? [2] [2] [5] [1]