C5 Work. Energy and Power Flashcards
1
Q
Converting from Joules to Nm
A
- 1J = 1Nm (1 joule is the work done when 1N moves 1m).
- Used in the context of work done, not moment)
2
Q
How much energy is transferred into GPE?
A
Work done directly against gravity is converted to GPE.
3
Q
Define energy
A
Energy is the capacity for doing work, a scalar quantity.
4
Q
Define kinetic energy with examples
A
- Energy due to the motion of an object with mass.
- Moving car, moving atoms.
5
Q
Define GPE with examples
A
- Energy of an object due to its position in a gravitational field.
- Child at the top of slide.
6
Q
Define chemical energy with examples
A
- Energy contained within the chemical bonds between atoms, it can be released when atoms are rearranged.
- Energy stored in a chemical cell.
7
Q
- Define elastic potential energy with examples
A
- Energy stored in an object as a result of its reversible change in its shape.
- A squashed spring.
8
Q
Define electrical potential energy with examples
A
- Energy of electrical charges due to their position in an electric field.
- Electrical charges on a thundercloud.
9
Q
Define nuclear energy with examples
A
- Energy within the nuclei of atoms, released when particles within the nucleus are rearranged.
- Energy from fusion/fission.
10
Q
Define electromagnetic energy with examples
A
- Energy associated with all EM waves, stored within their oscillating electric and magnetic fields
- Energy from an LED.
11
Q
Define sound energy with examples
A
- Energy of mechanical waves due to the movement of atoms.
- Energy emitted when you clap.
12
Q
- Define internal (heat/thermal) energy.
A
- The sum of the random potential and kinetic energies of atoms in a system.
- A hot cup of tea has more thermal energy than a cold one.
13
Q
Principle of conservation of energy
A
- Total energy of a closed system remains constant: energy can never be created of destroyed, but can be transferred from one form to another.
14
Q
Formula for GPE
A
mgh
15
Q
Power of a object when a constant force is needed to maintain a constant speed
A
P = Fv
