Work, Energy And Power

Question 1

Define work.

Answer 1

Work done on an object by a force is defined as the product of the displacement (s) and the component of force (Fnet) parallel to the displacement.

W = FNET(COSØ) X S

Question 2

Define Energy.

Answer 2

Energy is defined as the ability to do work.

Question 3

Define gravitational potential energy.

Answer 3

Gravitational potential energy is defined as the energy an object possesses due to its position relative to a point of reference.

Ep = MGH

Question 4

Define Kinetic energy.

Answer 4

Kinetic Energy is defined as the energy an object possesses by virtue of it’s motion.

Ek = 0.5M(V^2)

Question 5

Define an elastic collision.

Answer 5

An elastic collision is a collision in which the the total kinetic energy if the system is conserved ( Ek initial = EK final)

Question 6

Define an inelastic collision.

Answer 6

An inelastic collision is one in which the total kinetic energy if the system is not conserved but rather converted into other for s of energy such as heat, light and sound.

Question 7

State the principle of conservation of energy.

Answer 7

This principle states that the total energy in a system cannot be created or destroyed, only transferred from one form to another.

Question 8

State the principle of conservation of mechanical energy.

Answer 8

The principle of conservation of mechanical energy states that in the absence of air resistance or any external forces, the total mechanical energy of an object is constant.

Emech = EK + EP

Question 9

State the work energy theorem.

Answer 9

The work energy theorem states that the work done by the resultant force on an object is equal to the change in kinetic energy of that object.