A bungee jumper, of mass 49 kg, is attached to one end of a light elastic cord of natural length 22 metres and modulus of elasticity 1078 newtons. The other end of the cord is attached to a
horizontal platform, which is at a height of 60 metres above the ground. The bungee jumper steps off the platform at the point where the cord is attached and falls vertically. The bungee jumper can be modelled as a particle. Assume that Hooke's Law applies
whilst the cord is taut, and that air resistance is negligible throughout the motion.
When the bungee jumper has fallen x metres, his speed is v m s-1.
(a) By considering energy, show that when x is greater than 22,
562 = 318x - 5x2 _ 2420
(b) Explain why x must be greater than 22 for the equation in part (a) to be valid.
(c) Find the maximum value of x.
(d) (i)
Show that the speed of the bungee jumper is a maximum when. = 31.8.
(ji)
Hence find the maximum speed of the bungee jumper.