To whom it may or may not concern.

Work is the product of force and the displacement in the direction of that force. For work to be done. The applied force has to cause a body to move, meaning the resultant displacement must not be equal to zero. Example is pushing or pulling a box.

Question 1
If you push a chair of 20m forward by applying a force of 30N. What is the work you have done on the box?
Answer
work done = force x distance
force = 30N
distance = 20m
work done = 30 x 20
work done = 600 J (Unit of work is Joule)

Question 2
What is the work done if you try to push a drum of oil of by directing a force of 60N up the slope but instead it roles down 50m?
Answer
The distance and force are in opposite direction so we'll write it as force = -60N,distance = 50m
work done = -60 x 50m
work done = -300 J (meaning the drum does work on you)

Question 3
What is the work done when a box of mass 50kg slides down a lorry from a height of 400cm?
Answer
Here the invisible force of gravity is acting on the box. Force = mass x acceleration; Force = 50kg x 10m-2 (acc. due to gravity)
Force = 500 N
Distance = 400cm
but the distance is the wrong unit, so we shall convert to the proper S.I unit i.e metres.
Distance = 400cm x 1/100
Distance = 4m

Work done = Force x Distance; 500N x 4m
Work done = 2000Nm or 2000 J

Energy is the ability or capacity to do work. It is also measured in joules and it is a scalar quantity. Anything capable of doing work has energy e.g a falling fruit, a man throwing a ball.

There are various forms of energy. Some of which are;
1. Mechanical Energy
2. Electrical Energy
3. Light Energy
4. Solar Energy
5. Nuclear Energy
6. Thermal Energy
7. Sound Energy

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We get energy from the foods we eat, especially from energy giving foods like carbohydrates. The Sun (the real sun and not that newspaper), from burning fuels and also hydro energy from dams.

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An object with energy can do work. But when that work is done energy is lost by the object and gained by the object on which work was done.

If you kick a ball. You lose energy while the ball you kicked gains energy.
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