6.6 Equilibrium rules

Question 1

What happens when 2 objects interact?

Answer 1

» They exert equal and opposite forces on one another

Question 2

What does a free body force diagram show?

Answer 2

» Shows only the forces acting on the object

Question 3

For a point object acted on by three forces to be in equilibrium…?

Answer 3

» The three forces must given an overall resultant of zero
» 3 forces should form a triangle
» F1 + F2 + F3 = 0

Question 4

What must the lines of action do for an object to be in equilibrium?

Answer 4

» Must intersect at the same point

Question 5

What can a scale diagram of the triangle of forces find?

Answer 5

» An unknown force or angle

Question 6

What is an object equilibrium..?

Answer 6

» Is either at rest or moving at constant velocity

Question 7

What does a body have to do to be in equilibrium?

Answer 7

» The resultant force must be zero, if there are only three forces they must form a closed triangle
» The principle moments must apply