Energy tranfers - Pendulum

What is the law of conservation of energy

Energy can be transferred usefully, stored or dissipated but it cannot be created or destroyed

3 parts to a pendulum

Fixed point

String

Mass

What is a system

An object or a group of objects

Energy in a closed system

In a closed system, no energy can enter or leave

Describe the energy transfers of a pendulum

At the highest point of swing, there is a maximum gravitational potential energy of the mass. As the pendulum swings, it is transferred to kinetic energy store. At the bottom, there is maximum kinetic energy store of mass as it is moving fastest there. As it swings back up, the kinetic energy is transferred to gravitational potential energy again

What else is there in a pendulum

Friction

There is friction in the fixed point and friction as the pendulum passes through the air particles

What does friction cause energy to become

Causes energy to be transferred to thermal energy. This thermal energy caused the fixed point and the air around the pendulum to gradually get warmer

How would we describe the thermal energy store in a pendulum swing

Less useful. The energy has been dissipated (wasted). This will cause the pendulum to gradually swing with less energy and stop

What does dissipated mean

Wasted

How can we reduce unwanted energy transfers in pendulum

Reduce friction

How to reduce friction in the pendulum swing

Use a lubricant (eg oil on the fixed point)

Remove the air particles from around the pendulum