What type of simple machine is a screw? Inclined plane
When a screwdriver is used as a lever to open a paint can, what is changed as the work is done? Size and direction of input force
What is a device that makes work easier by changing the size or direction of force? machine
What is a machine with a grooved wheel that holds a cable? pulley
Which of the following is a compound machine? First class lever Wheel and axle Block and tackle pulley Screw
What is it called when a force causes an object to move in the direction of the force? work
If a book weighs 50 N, what other information do you need to calculate how much work is done when it is lifted? W = F x d….Distance
Where is the input force of a wheel and axle exerted? A circular distance
How does a ramp make lifting a heavy object easier? Less force is needed to move the object over a longer distance
Which of the following are simple machines used by the Egyptians to build pyramids? Inclined planes and levers Wheels and axles Screws and screwdrivers Plows and axes
Which of the following is NOT a wedge? Chisel Knife Plow Ramp
What is the work done BY an object? Work output
A doorknob is an example of a Wheel and axle
What is a machine that is made of two simple machines? Compound machine
Susie and Fred are lifting bags of fruit to put in a truck. Susie does 200 J of work in 5 minutes and Fred does 200 J of work in 3 minutes. What was the difference between the two jobs? The power! P = Work/time
What does a fixed pulley change? The direction of a force
James applies a force of 100 N to move a table 3 meters. How much work did he do? W= F x d W= 100N x 3 m W= 300J
If you unwind a screw, you would find that is actually a(n) Inclined plane
A _________lever places the load between the input force and the fulcrum. 2 nd class REMEMBER: What is in the MIDDLE of the lever? 1 st : Fulcrum 2 nd : Output Force 3 rd : Input Force
A _______pulley is attached to something so it does not move. fixed
After you exert a force on an object, it then moves and has __________energy. Kinetic
The mechanical advantage of a block and tackle pulley depends upon the number of _______ Rope segments
A lever where the fulcrum is between the input force and load: 1 st class Think see-saw
A lever where the load is between the input force and fulcrum 2 nd class (think…wheel barrow)
A pair of incline planes that move wedge
A machine that consists of 2 circular objects of different sizes Wheel and axle
A machine that is a straight, slanted surface Inclined plane
A machine that has a bar that pivots at a fixed point lever
A machine with a grooved wheel holding a rope pulley
A lever where the input force is between the fulcrum and the load 3 rd Think….hammer hammering a nail
A fixed point on a lever fulcrum
Unit for Power Watt
Unit for Work Joule
What is difference between 3 classes of levers? Where output force is
What type simple machine would Reggie be using if he was trying to get a nail out of a piece of lumber? 1 st class….fulcrum at end!