In a given frictionless displacement of a particle,its kinetic energy increases by 25 J while its potential energy decreases by 10 J.Determine the work of the nonconservative forces acting on the particle during this displacement.
A)-15 J
B)+35 J
C)+15 J
D)-35 J
E)+55 J

Question

Quizplus · Accepted Answer

According to the conservation of mechanical energy, the sum of kinetic energy and potential energy should remain constant in the absence of external forces. However, in this case, we see a change in both kinetic and potential energy, indicating the presence of nonconservative forces.

The work done by nonconservative forces is given by the difference between the initial and final mechanical energies:

Work of nonconservative forces = (Initial mechanical energy) - (Final mechanical energy)
                            = (Kinetic energy + Potential energy)_initial - (Kinetic energy + Potential energy)_final
                            = (25 J + (-10 J)) - (0 J + 0 J)
                            = 15 J

Therefore, the correct answer is C) +15 J.

In a Given Frictionless Displacement of a Particle,its Kinetic Energy