Physics - Energy Stores + Systems

What is Energy?

Energy is never created or destroyed and is only transferred between different forms and objects.

What are the energy stores?

• Thermal

• Kinetic

• Gravitational Potential

• Elastic

• Chemical

• Magnetic

• Electrostatic

• Nuclear

What is Thermal?

Heat energy

What is Kinetic?

Movement or motion of an object

What is Gravitational Potential?

Position in a gravitational field

What is elastic?

Energy already held in a stretched string

What is chemical?

Held in chemical bonds.

What is magnetic?

Holds magnets to surfaces.

What is electrostatic?

Gives an electric shock.

What is nuclear?

Energy obtained from breaking atoms apart.

What are the transfers of energy?

• Mechanical

• Electrical

• Heating

• Radiation

What does the transfer of energy mean?

The process of energy moving from one store to another.

What is an energy system?

A group of objects is called a system and when the system changes, energy is transferred, either between objects or different forms.

What’s an open system?

Can lose or gain energy as it connects with the outside world.

What’s a closed system?

Is NOT connected with the outside world so neither matter or energy can enter or leave but energy can still be transferred in the system.

What is always the over all change?

0 (ZERO)

What are the two “work done”

• Mechanical

• Electrical

What is mechanical?

Using force to move an object e.g. kicking a ball.

What is electrical?

When current flows e.g. energy required to overcome the resistance in wires of circuit.

What is the formula for “Kinetic Energy”?

Ek = ½ m v*2

• Ek = Kinetic Energy

• ½ = 0.5

• M = Mass (kg)

• V*2 = Velocity/Speed (m/s)

What is kinetic energy measured in?

Joules

What is the gravitational field strength?

9.8 newtons (kg)

Force of attraction = objects weight

What’s the formula for weight?

Weight (w) = mass (kg) x gravitational field strength.

W=mg

What’s the formula for gravitational potential energy?

GPE/Ep = mgh

• Ep = Gravitation potential energy

• M = Mass (kg)

• G = Gravitational field strength (n/kg)

• H = Height (m)

What is internal energy?

The total energy stored by the particles moving up a system or substance.

What are the potential energy stores?

• Gravitational

• Elastic

What are the kinetic energy stores?

The movement energy of the particles.

What happens when you heat up something?

It goes to its kinetic energy store, increasing their internal energy and you measure it as an increase in temperature because temperature is just a measure of the average internal energy of a substance.