Question

Ignoring details associated with friction, extra forces exerted by arm and leg muscles, and other factors, we can consider a pole vault as the conversion of an athlete's running kinetic energy to gravitational potential energy. If an athlete is to lift his body 3.8 m during a vault, what speed (in m/s) must he have when he plants his pole

Answer 1

v = 8.63 m/s

Step-by-step explanation:

Neglecting the frictional forces, the law of conservation of energy can be applied to this situation as follows:

Potential Energy Gained By Athlete = Kinetic Energy Lost By Athlete

mgh = (0.5)mv²

gh = (0.5)v²

v = √2gh

where,

v = speed that the athlete must have when he plants the pole = ?

g = acceleration due to gravity = 9.8 m/s²

h = Height to be achieved by the athlete = 3.8 m

Therefore,

v = √(2)(9.8 m/s²)(3.8 m)

v = 8.63 m/s