6.6- EQUILIBRIUM RULES

Question 1

When two objects interact, what do they always exert?

Answer 1

equal + opposite forces on one another

Question 2

What does a free body diagram only show?

Answer 2

only the forces acting on the object

Question 3

For a point object acted on by three forces to be in equilibrium, what must the three forces give?

Answer 3

overall resultant of zero

Question 4

What should the three forces acting on a point object form as vectors?

Answer 4

a triangle

Question 5

What must the line of actions of the three forces acting on a body in equilibrium do and why?

Answer 5

must interact at the same point, otherwise body cannot be in equilibrium, as forces will have a net turning effect

Question 6

When can an object be in equilibrium?

Answer 6

at rest or moving with constant velocity

Question 7

When an object is in equilibrium, what is the resultant force of the forces acting on it? (2)
(2- turning effect)

Answer 7

zero

turning effects balance out well

Question 8

For a body to be in equilibrium, what must be present? (2)

Answer 8

resultant force 0- if only 3 forces, must form closed triangle

principle of moments must apply