1.3 Principle of Moments

Question 1

what is the moment of a force dependent on?

Answer 1

size of force
distance between force and pivot

Question 2

perpendicular distance

Answer 2

distance from the pivot to line of action of the force

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

unit of a moment

Answer 4

Nm or Ncm

Question 5

moment equation

Answer 5

m = f x d

Question 6

centre of gravity

Answer 6

point at which weight of object is considered to act

Question 7

centre of mass

Answer 7

point at which mass appears to be concentrated
doesn’t depend on gravitational field

Question 8

stable objects characteristics

Answer 8

wide base
low centre of gravity

Question 9

principle of moments

Answer 9

for a body in rotational equilibrium, the sum of the clockwise moments about a point are equal to the sum of the anticlockwise moments about the same point

Question 10

principle of moments equation

Answer 10

ACM = CM

Question 11

conditions for body to be in full equilibrium

Answer 11

sum of ACM - sum of CM about the same point (rotational equilibrium)
no resultant force (translational equilibrium)

Question 12

what happens to an object in equilibrium

Answer 12

remains at rest or moving at a constant velocity