Answer:
71 J
Step-by-step explanation:
You want the energy lost to non-conservative forces when a 0.76 kg ball is dropped from a height of 22 m and impacts the ground at 15.6 m/s.
Potential energy
The potential energy of the ball is ...
PE = mgh
PE = (0.76 kg)(9.8 m/s²)(22 m) = 163.856 J
Kinetic energy
The kinetic energy the ball has when it strikes the ground is ...
KE = 1/2mv²
KE = 1/2(0.76 kg)(15.6 m/s)² = 92.4768 J
Lost Energy
The energy lost during the fall is ...
PE -KE = lost energy
163.856 -92.4768 = 71.3792 . . . joules
About 71 joules of mechanical energy is lost.