Different types of energy:
Potential:
Gravitational potential energy:
The potential of an object to do work because of its relative position.
E.g. A ball held in the air.
Elastic potential energy:
The energy stored in an object when it is stretched or deformed.
E.g. A stretched rubber band.
Chemical potential energy:
The energy stores in the bonds between atoms, released as heat, sound or light
during chemical reactions such as burning.
E.g. Batteries
Nuclear potential energy:
The energy stored in the nucleus of atoms, it may be released quickly as a
nuclear explosion or controlled slowly in a nuclear reaction.
E.g. Nuclear fission
Active:
Kinetic energy:
The energy that an object has because of its movement
E.g. A thrown ball.
Heat energy:
The motions of atoms or molecules in a substance or object
E.g. The sun.
Sound energy:
The vibration of particles that can be detected by the ear.
E.g. A loud clap.
Light energy:
A form of electromagnetic radiation emitted by hot objects. It is usually visible
light.
E.g. A torch beam.
Electrical energy:
The energy generated by moving electrons.
E.g. Lightning.
, Energy transformations
An energy transformation is the conversion of one form of energy into
another form.
E.g. Solar panels: Light to heat.
Torches: Electrical to light and heat.
Battery: Chemical to electrical.
A swing: Gravitational potential to kinetic to gravitational potential.
The sun: Nuclear to light and heat.
Energy transfers
An energy transfer is the movement of the same energy form from one
object to another.
E.g. A bowling ball hitting another bowling ball.
Me punching someone.
Electricity going along a wire.
Heat going from a hot pan to my hand when I burn myself.
Sound going through a wall.
Kinetic energy of an object
1 1
( Energy ∈ joules )− ( Mass∈kg ) ( Velocity∈meter per second )2 E= M V 2
2 2
Example q’s: An 800kg car is driving at 2m/s. What is its energy?
½x800x(2x2) = 1,600J
A car that weighs 1 ton is driving at 5m/s. What is its energy?
½x1000x25 = 12,500J
Gravitational potential energy of an object
( Energy ∈ joules )−( Mass∈kg ) ( Height∈meters)(Gravitational force which equal10 on earth)
E=MHG
Example q’s: A 6kg ball is being held 50 meters off the ground. How much
gravitational potential energy does the ball have?
6x50x10 = 3,000J of gravitational potential energy.
A 40kg person is being held 8 meters off the ground. How much gravitational
potential energy does the person have?
40x8x10 = 3,200J of gravitational potential energy.
Principle of the conservation of energy
Potential:
Gravitational potential energy:
The potential of an object to do work because of its relative position.
E.g. A ball held in the air.
Elastic potential energy:
The energy stored in an object when it is stretched or deformed.
E.g. A stretched rubber band.
Chemical potential energy:
The energy stores in the bonds between atoms, released as heat, sound or light
during chemical reactions such as burning.
E.g. Batteries
Nuclear potential energy:
The energy stored in the nucleus of atoms, it may be released quickly as a
nuclear explosion or controlled slowly in a nuclear reaction.
E.g. Nuclear fission
Active:
Kinetic energy:
The energy that an object has because of its movement
E.g. A thrown ball.
Heat energy:
The motions of atoms or molecules in a substance or object
E.g. The sun.
Sound energy:
The vibration of particles that can be detected by the ear.
E.g. A loud clap.
Light energy:
A form of electromagnetic radiation emitted by hot objects. It is usually visible
light.
E.g. A torch beam.
Electrical energy:
The energy generated by moving electrons.
E.g. Lightning.
, Energy transformations
An energy transformation is the conversion of one form of energy into
another form.
E.g. Solar panels: Light to heat.
Torches: Electrical to light and heat.
Battery: Chemical to electrical.
A swing: Gravitational potential to kinetic to gravitational potential.
The sun: Nuclear to light and heat.
Energy transfers
An energy transfer is the movement of the same energy form from one
object to another.
E.g. A bowling ball hitting another bowling ball.
Me punching someone.
Electricity going along a wire.
Heat going from a hot pan to my hand when I burn myself.
Sound going through a wall.
Kinetic energy of an object
1 1
( Energy ∈ joules )− ( Mass∈kg ) ( Velocity∈meter per second )2 E= M V 2
2 2
Example q’s: An 800kg car is driving at 2m/s. What is its energy?
½x800x(2x2) = 1,600J
A car that weighs 1 ton is driving at 5m/s. What is its energy?
½x1000x25 = 12,500J
Gravitational potential energy of an object
( Energy ∈ joules )−( Mass∈kg ) ( Height∈meters)(Gravitational force which equal10 on earth)
E=MHG
Example q’s: A 6kg ball is being held 50 meters off the ground. How much
gravitational potential energy does the ball have?
6x50x10 = 3,000J of gravitational potential energy.
A 40kg person is being held 8 meters off the ground. How much gravitational
potential energy does the person have?
40x8x10 = 3,200J of gravitational potential energy.
Principle of the conservation of energy
