Chapter 3: Forces

Question 1

State Hooke’s Law

Answer 1

The change in an object’s length is directly proportional to the applied force (F = kx)

Question 2

Define upthrust

Answer 2

It is the upwards force exerted by a fluid on a partially or fully submerged object due to a difference in pressure exerted on the upper and lower surfaces of the object by the fluid

Question 3

Define the moment of a force about a point

Answer 3

It is the product of the force exerted at that point and the perpendicular distance of the line of action of that force from that point

Question 4

Define the torque due to a couple

Answer 4

It is the product of the magnitude of one of the forces and the perpendicular distance between the 2 forces.

Question 5

State the Principle of Moments

Answer 5

It states that the sum of all clockwise moments about a point is equal to the sum of all anticlockwise moments about the same point

Question 6

Equilibrium is only achieved when…

Answer 6

1) There is no resultant force on a body
2) There is no resultant torque on a body