Revision Chapter 7 Form 3

_______ is defined as the product of force and displacement.

one joule =

• 10 Nm

• 100 Nm

• 1 Nm

• 1000Nm

calculate the work done if a student weighing 400 N carrying a load 200 N while climbing a flight of stairs of a vertical height of 3 m.

Ali lifting a box of mass 10 kg from the floor to the top of a cupboard. If the height of cupboard is 1.5 m, calculate the work done by Ali.

• 1.5 J

• 15 J

• 150 J

• 1500J

A labourer pulled a bucket of cement weighing 400 N from the ground to the first floor using a pulley system. The first floor is 10 m from the ground. Calculate the work done by the labourer.

________ is define as the ability to do work.

______ is defined as the rate of doing work.

1 W =

• 1 J

• 1 s

• 1 J /s

• 1 N

Gravitational potential energy =

Elastic potential energy =

• mgh

• 1/2 Fx

• mg

• Fs