Question

When Brian, whose mass is 66 kg, jumps from the roof of his house onto a trampoline 3.2 m below, the trampoline sags 22 cm at its maximum deformation.

(a) How much energy is lost to heat and sound in the trampoline if Brian bounces back only 1.0 m above the level of the trampoline?

Answer 1

Ans:

a) Choosing the ground to the reference of the potential energy,

Choosing intital point when Brian jumps from the roof, and final point when we bounces back to 1.0 m

So the energy lost = initial energy - final energy = mgh_I - mgh_f = 66*9.8(3.2-1.0) = 1422.96 J.

So the energy lost to heat ans sound in the trampoline = 1422.96 J