P1 - Using Energy Flashcards
When an object falls to the ground how does its energy change?
Its GPE is transferred to KE.
Name the ten forms of energy.
- Chemical
- Kinetic
- Gravitational Potential
- Elastic Potential
- Electrical
- Sound
- Heat
- Light
- Nuclear
- Magnetic
When an object hits the ground how does its energy change?
The KE is transferred to heat and sound energy.
What does the conservation of energy tell us?
Energy cannot be created nor destroyed.
How does the amount of energy change?
The amount of energy is always conserved.
What is useful energy?
Energy transferred to where it is wanted and in the correct form.
What is wasted energy?
Energy that has no use.
What happens to wasted energy?
Energy eventually dissipates to its surroundings, making them warmer.
What is weight measured in?
Newtons, because weight is a force.
What is energy measured in?
Joules
What does input energy equal?
Useful energy + wasted energy
How is efficiency calculated as a percentage?
(Useful energy / input energy) x 100
Why can’t a machine be more than 100% efficient?
Due to the conservation of energy, it is not possible to get more energy than the input.
Give four measures that make a machine more efficient.
Reducing:
- Friction
- Air resistance
- Electrical resistance
- Noise from vibrations
