Forces Definitions

Question 1

Hooke’s law

Answer 1

Hooke’s law states that within the limit of proportionality, the extension produced in a material is directly proportional to the load applied.

Question 2

Centre of mass

Answer 2

The centre of mass of a body is the point at which the entire mass of the body can be considered to act.

Question 3

Centre of gravity

Answer 3

The centre of gravity (c.g.) of a body is the point at which the entire weight of the body can be considered to act.

Question 4

Moment of force

Answer 4

The moment of a force is defined as the product of the force and the perpendicular distance between the axis of rotation and the line of action of force

Question 5

Couple

Answer 5

A couple is a pair of equal and opposite forces acting on a body and their lines of actions do not coincide

Question 6

Torque of a couple

Answer 6

The torque of a couple is the product of one of the forces and the perpendicular distance between their lines of action

Question 7

Conditions for equilibrium

Answer 7

1. The resultant force is zero
2. The resultant moment about any axis is zero

Question 8

Hydrostatic pressure

Answer 8

Hydrostatic pressure is the pressure that is exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity.

Question 9

Archimedes’ principle

Answer 9

Archimedes’ principle states that upthrust is equal to the weight of the fluid displaced by a submerged or floating object