5 Written questions
5 Matching questions
- What is a pulley?
- ^ <--- Doing work?
- what is mechanical efficiency?
- What are compound machines?
- And example of a wedge.
- a Doorstop. it holds things together.
- b a machine made of two or more simple machines. example: scissors, can openers
- c 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.
- d No
- e simple machine that is made of a wheel with a groove in it and a rope. it is usually used to life heavy objects.
5 Multiple choice questions
- P=W / T, the unit Watts
- a simple machine that has a fulcrum, or pivot point.
- the rate at which work is done.
- we need to know the size of the force that was put on the object, and how far the object moved.
- a simple machine with a straight, slanted surface.
5 True/False questions
^ ---> Doing work? → Yes
what is a machine? → a double inclined plane that moves.
what is a machine's mechanical advantage? if i say a machine has a mechanical advantage of 20, what does that mean? → 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.
If machines do not reduce the amount of work being done, how do they help us? → Machines can change the size of the input force necessry. Also, they can change the direction of the force, which is especially helpfulo when we are trying to life somthing.
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.