calculating forces

Question 1

What happens if all forces acting on a object combine to give a resultant force of 0

Answer 1

the object is in equilibrium

Question 2

How do you show an object is in equilibrium on a scale diagram?

Answer 2

• add a missing line from the end of the last line to the start of the first
  -usually a triangle
• measure its direction and magnitude

Question 3

What do you do when you have a awkward line?

Answer 3

• add horizontal and vertical line to form right angle