5 Written Questions
4 Matching Questions
- what is mechanical efficiency?
- ^ ^ Doing work?
- ^ ---> Doing work?
- What is "power", scientifically speaking?
- a No
- b Yes
- c the rate at which work is done.
- d is a measure of how much of a machines energy is wasted, overcoming friction. No machine is 100% efficient, becuase there are always surfaces rubbing together.
5 Multiple Choice Questions
- pushing a piece of heavy furniture up a ramp requires less input force, from you, than just lifting it up.
- W= F x D, the unit Joule
- a device that helps make work easier by changing the size or direction of a force.
- P=W / T, the unit Watts
5 True/False Questions
example of a wheel and axle. → a simple machine that is made of a circular object connected to a rod.
What is a pulley? → simple machine that is made of a wheel with a groove in it and a rope. it is usually used to life heavy objects.
What two things do we need to know to calculate work? → we need to know the size of the force that was put on the object, and how far the object moved.
if you are pushing against a wall, are you doing work? explain. → you are only doing work on the ball as long as you are directly putting a force on it, in other words, when you are touching it.
if you throw a ball, are you doing work? Explain. → you are only doing work on the ball as long as you are directly putting a force on it, in other words, when you are touching it.