Question

The platform height for Olympic divers is 10 m. A 60 kg diver steps off the platform to begin her dive. a. How much gravitational potential energy does the diver have? 2. LOL b. How much kinetic energy does the diver have as she strikes the water? c. How much work does the water do on the diver to stop her motion? d. If the diver stops in 2.5 m after entering the water, what net force is applied to the diver?

Answer 1

here,

the initial height of plateform , h0 = 10 m

mass of diver , m = 60 kg

a)

the gravitational potential energy doe the diver have , PE0 = m * g * h0

PE0 = 60 * 9.81 * 10 J = 5886 J

b)

when it strikes the water

using conservation of mechanical energy

the kinetic energy of the diver , KE = PE0 = 5886 J

c)

using Work energy theorm

the work done by water to stop , W = change in kinetic energy

W = ( 0 - KE) = - 5886 J

d)

let the net force applied on the diver be F

W = F * s * cos(180)

- 5886= F * 2.5 * cos(180)

F = 2354.4 N

the net force applied on the diver is 2354.4 N