Energy

YOU ARE LEARNING:

Understanding Work

The term Work Done can be described in terms of energy transferred, which we will calculate using force and distance.

What is the unit for energy?

If you go to the gym and do a work out, which of the following is your body using up?

When we talk about work done in physics, we are not talking about 8 hours in the office or having handed in our homework. We are talking about energy which has been transferred from one store to another.

Which of these examples of work done requires the most energy, do you think?

The amount of work done is equivalent to the amount of energy transferred. So when we as physicists are asked "How much work did you get done today?", we should really answer something like: "2000 Joules worth!"

If your car broke down, and you had to push it home, which of the following would affect the amount of work you would have to do to get the car home?

You can select multiple answers

Weight is a type of ...

If weight is a type of force and distance affects work done, then which of the following is the formula for work done to move an object, where $W$ is work done, $F$ is force, and $d$ is distance?

The work done in moving an object is the same as the force required to move the object, multiplied by the distance the object is moved:

So $W=F\times d$ , where $W$ is work done in Joules, $F$ is force in Newtons, and $d$ is distance in metres.

If work done is measured in Joules and energy is also measured in Joules, is it then correct to say that work done in moving an object is equal to energy transferred whilst moving that object?

The work done in moving an object is the same as the energy transferred in the system.

We can therefore say that $E=F\times d$ , where $E$ is energy transferred, as well as $W = F \times d$ , where $W$ is work done, because energy and work done are ultimately the same thing.