Answer :
The initial mechanical energy is the potential energy (PE) which can be solved through the equation,
PE = mgh = (40 kg)(9.8 m/s²)(12 m) = 4,704 J
The energy at the bottom is the kinetic energy and can be calculated through the equation,
KE = 0.5mv² = (0.5)(40 kg)(10 m/s)² = 2000 J
Therefore, she lost 2,704 J of energy due to friction
PE = mgh = (40 kg)(9.8 m/s²)(12 m) = 4,704 J
The energy at the bottom is the kinetic energy and can be calculated through the equation,
KE = 0.5mv² = (0.5)(40 kg)(10 m/s)² = 2000 J
Therefore, she lost 2,704 J of energy due to friction