Work, Energy and Power

Question 1

the work done on an object

Answer 1

By a constant force F as F
magnitude of the force, Δx the magnitude of the displacement and the angle between the force and the displacement.

Question 2

the work-energy theorem

Answer 2

The work done on an object by a net force is equal to the change in the object’s kinetic energy OR the work done on an object by a net force
is equal to the change in the object’s kinetic energy.

Question 3

the work-energy theorem

Answer 3

The work done on an object by a net force is equal to the change in the object’s kinetic energy OR the work done on an object by a net force
is equal to the change in the object’s kinetic energy.

Question 4

conservative force

Answer 4

a force for which the work done in moving an object
between two ponts is independent of the path taken.

Question 5

a non-conservative force

Answer 5

a force for which the work done in moving an object
between two points depends on the path taken.

Question 6

the principle of conservation of mechanical energy

Answer 6

The total mechanical energy
(sum of gravitational potential energy and kinetic energy) in an isolated system remains
constant.

Question 7

isolated system

Answer 7

The net external force (excluding the
gravitational force) acting on the system is zero.

Question 8

power

Answer 8

The rate at which work is done or energy is expended.