Energy is measured in:

1.   ?    Joules
2.   ?    Watts
3.   ?    Degrees Celsius
4.   ?    Kilograms

Thermal is a physics word associated with:

1.   ?    Convection
2.   ?    Insulation
3.   ?    Heat
4.   ?    Units on a gas bill

Which one of these best describes the Law of Conservation of Energy?

1.   ?    It's a Law that says that large energy users such as schools and factories must save energy.
2.   ?    Energy can be created but not destroyed.
3.   ?    Energy cannot be created but can be destroyed.
4.   ?    Energy can neither be created nor destroyed.

Which one is true about the energy given by a motor?

1.   ?    The energy got out is more than the energy put in.
2.   ?    The energy got out is less than the energy put in.
3.   ?    The energy got out is equal to the energy put in.
4.   ?    Energy is neither put in nor got out.

Whenever a machine does a job of work, some energy goes into doing the work. The rest:

1.   ?    goes back to the source.
2.   ?    is destroyed.
3.   ?    is wasted to heat up the surroundings.
4.   ?    is wasted to cool down the surroundings.

The units for efficiency are usually:

1.   ?    Percent (%)
2.   ?    Joules (J)
3.   ?    Degrees Celsius
4.   ?    Kilograms (kg)

The formula for efficiency is:

1.   ?    Efficiency = (energy in ÷ energy out) × 100 %
2.   ?    Efficiency = (energy out - energy in) × 100 %
3.   ?    Efficiency = (energy out × energy in) × 100 %
4.   ?    Efficiency = (energy out ÷ energy in) × 100 %

The most like efficiency for a steam engine is:

1.   ?    0.1 %
2.   ?    10 %
3.   ?    100 %
4.   ?    1000 %

A petrol engine is 33 % efficient. This means that for every 2000 J of petrol burned:

1.   ?    6.6 J of energy is turned into movement energy.
2.   ?    66 J of energy is turned into movement energy.
3.   ?    660 J of energy is turned into movement energy.
4.   ?    66000 J of energy is turned into movement energy.

A petrol engine is 33 % efficient. This means that for every 2000 J of petrol burned:

1.   ?    64 000 J is wasted as heat
2.   ?    2000 J is wasted as heat
3.   ?    1934 J is wasted as heat
4.   ?    1340 J is wasted as heat.