Unit 5 summary

What did I learn this unit?

Work and power

            Work = (Force) (Distance), this simple equation has a few rules though; the force and distance must not be perpendicular. If this occurs then no work is done.  Even if you apply force on a wall for instance, and the wall doesn’t move know work is done since there was no distance component.  Work is calculated in a unit called Jules. 746 Jules equal 1 horsepower. Power is calculated by dividing work by time. Power is calculated in units named watts.

Work and Kinetic Energy

            Change in Kinetic energy is equal to work. In this way the two are very closely connected. The formula for Kinetic energy is shown below. Kinetic is moving energy, while potential energy is stored energy.

Simple machines

            Simple machines do not change the amount of work to finish a task. Machines simply lengthen the distance so a lesser force is needed. Work in equals work out. A ramp which is a simple machine spreads the distance of lifting an item from 1 meter to 4, so only ¼ the force  is needed. Still creating the same amount of work.

Formulas from the unit

·         Work = (Force)(Distance)
·         Power = Work / Time
·          Kinetic Energy = ½ Mass ( velocity^2)
·         Potential Energy = Kinetic Energy
·         Change in kinetic energy = Work
·         Work in = Work out

How is this relevant in the outside world?

            Work and simple machines are found everywhere. Simple machines create the world around us, and without them there would not be food on the table, electricity to power our lights, or even lights to be turned on. Work is everywhere, even whenever we move up and down for instance.

Podcast Video on Simple Machines