turning on a pivot

turning on a pivot

By the end of the lesson you will understand

what is lever.

parts of lever

types of lever

examples of lever and the principle of moments

Lever

Archimedes studied levers scientifically.

what is a lever?

A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself.

Multiple Select

Read page no 190 and find the three points/parts of the lever

• fulcrum

• funnel

• effort

• load

Lever

• A device that changes the direction in which a force acts is called lever

• Lever acts as a force multiplier

• Fulcrum : the support about which a lever turns

• Effort: The force applied to the lever

• Load: The object that you lift or the object that opposes the movement of lever.

Types of lever

• F. FULCRUM IS IN MIDDLE

• R. RESISTANCE OR LOAD IS IN MIDDLE

• E. EFFORT IS IN MIDDLE

Moment

• Turning effect produced by a force around a fulcrum is called moment.

• Direction of movement is either clock wise or anticlockwise.

• 
  

Law of moment

When an object is balanced (in equilibrium) the sum of the clockwise moments is equal to the sum of the anticlockwise moments. Force 1 x its distance from pivot = Force 2 x distance from the pivot.

Multiple Choice

A force of 4 N acts on a lever 2 m from the pivot.

What is the moment?

• 2 Nm

• 4 Nm

• 6 Nm

• 8 Nm

Multiple Choice

What will happen to the seesaw when both

people get on?

• it will turn in a clockwise direction.

• it will balance

• it will turn in an anti-clockwise direction

• it will turn either in an anticlockwise or

  clockwise direction