forces

Question 1

Hooke’s Law (spring)

Answer 1

within the limit of proportionality, the extension produced in a material is directly proportional to the force applied

Question 2

centre of gravity

Answer 2

the point at which the whole weight of the body appears to act through

Question 3

moment of a force

Answer 3

product of the force and the perpendicular distance from the line of action of the force to the pivot.

Question 4

couple

Answer 4

pair of forces acting on the same body that are equal in magnitude and opposite in direction and produce rotation only

Question 5

torque of a couple

Answer 5

turning effect of a couple is equal to the product of one of the forces of the couple and the perpendicular distance between the lines of action of the forces.

Question 6

Principle of Moments

Answer 6

for a body in rotational equilibrium, the sum of clockwise moments about any axis of rotation/pivot is equal to the sum of anti-clockwise moments about the same axis/pivot

Question 7

upthrust

Answer 7

equal in magnitude and opposite direction to the weight of the fluid displaced by a submerged or floating object.

Question 8

principle of flotation

Answer 8

for an object floating in equilibrium, the upthrust is equal to the magnitude and opposite in direction to the weight of the object.