What type of simple machine is a screw
- Slides: 35
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? l l 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? l l Inclined planes and levers Wheels and axles Screws and screwdrivers Plows and axes
Which of the following is NOT a wedge? l l 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? l l l W= F x d W= 100 N x 3 m W= 300 J
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…. 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!