Turning Effects of forces

Question 1

What is moment?

Answer 1

The turning effect of a force about a pivot is it’s moment

Question 2

Bullet points - Moment

Answer 2

➢ The moment of a force is bigger if the force is bigger.
➢ The moment of a force is bigger if it acts further from the pivot.
➢ The moment of a force is greatest if it acts at 90° to the object it acts on.
➢ If the beam is to be balanced, the moments of the two forces must cancel out each other.

Question 3

What is Equilibrium?

Answer 3

➢ When a beam is balanced, we say that it is in equilibrium.

Question 4

Conditions for equilibrium to take place

Answer 4

➢ The forces acting on it must be balanced (no resultant force)
➢ The turning effect of the forces must also be balanced (no resultant turning effect)

Question 5

Moment Formula

Answer 5

Moment of a force = Force x Perpendicular distance from pivot to force

Unit of moment = Nm ( Newton meter)

Total clockwise moment = total anti-clockwise moment

Question 6

What is the principle of moments?

Answer 6

The idea that an object is balanced when clockwise and anti-clockwise moments are equal is known as the principle of moments

Question 7

Bullet points - Center of mass

Answer 7

➢ All of an object’s mass is concentrated at a point, known as the center of mass

➢ For an stable object, the center of mass should be lower and the base should be wider.