5 Written questions
5 Matching questions
- example of a wheel and axle.
- what is mechanical efficiency?
- What is the formula for power?
- ---> ----> Doing work?
- what is a machine's mechanical advantage? if i say a machine has a mechanical advantage of 20, what does that mean?
- a 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.
- b turn a door knob (the wheel) the axle moves, to unfasten the door.
- c it means that the machine multiplies the force you put into it twenty times. so, if the machine multiplies the force by 20, you would only have to put in a small amount of force to do a large amount of work.
- d P=W / T, the unit Watts
- e Yes
5 Multiple choice questions
- a double inclined plane that moves.
- stays still, like the middle of a seesaw.
- a inclined plane that is wrapped in a spiral, usually on a rod, but not always.
- a simple machine that is made of a circular object connected to a rod.
5 True/False questions
if you are carrying a suitcase,are you doing work on the suitcase? why or why not? → No. work is only done when the object moves. if the object doesnt move, no matter how much force you put on it, it isnt work.
What is a lever? list two other examples of a lever. → a simple machine that has a fulcrum, or pivot point.
What is the scientific meaning of the word "work"? → Work happens when a force causes an object to move in the same direction of that force.
What is the formula to calculating work? → W= F x D, the unit Joule
What is "power", scientifically speaking? → the rate at which work is done.