1- what is a machine? 2- what do we mean my "energy"
3- what are fuels?
4-how do we measure energetic change?
5- what is efficiency?
6- what kind of machines are theres

1) A machine is an apparatus using or applying mechanical power and having several parts, each with a specific function.

2) Energy is the capacity of a physical system to do work.

3) Fuels are any material that can be made to react with other substances so that it releases energy as heat energy or to be used for work.

4) Measure a volume of an acid and place into a polystyrene cup which is placed into a beaker.
Measure the temperature of the acid with a thermometer.
Add a measured volume of an alkali to the acid.
Measure the temperature rise to calculate the energy change.

5) the ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in; an action designed to achieve efficiency.

6) Pulley, lever, screw, and inclined plane.

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