Simple machines Flashcards
A force applied to the end of a lever to lift a load is called a
Effort force
A support on which a lever rests while moving or lifting an object is called a
Fulcrum
The force of an object on a lever is called a
Load
An inclined plane that is wrapped in a spiral
Screw
Made of one or more bars resting on a support
Lever
A slanted surface
Inclined plane
A grooved wheel with a rope or chain around it
Pulley
Made of one or two inclined planes
Wedge
Do simple machines reduce the amount of work? Explain using an example
Yes. If you have a box and you need to lift it a tall height you can get an inclined plane so you can just push the box up the inclined plane instead of lifting the box over a tall height
What type of simple machine is a doorknob?
Wheel and axle
A screwdriver is a wheel and axle. What part of a screwdriver is the wheel?
The handle
What part of a screwdriver is the axle?
The end part
Why is the crank on a meat grinder larger than the crank on a pencil sharpener?
It’s bigger on a meat grinder because it requires more force
Two or more inclined planes that are joined together to make a sharp edge or point form a —–
Wedge
The angle of an inclined plane affects the amount of ——– needed to lift an object
Force
The longer and less steep the inclined plane the (more or less) force it takes to lift an object
Less
Describe a first class lever
The fulcrum is in the middle and the load and effort are on opposite ends.
Effort Load
-––————————————————-
Fulcrum
Describe a second class lever
The load is in the middle, the effort and fulcrum are at opposite ends
Load Effort -------------------------------------------------------- Fulcrum
Describe a third class lever.
The effort is in the middle, with the load and fulcrum at opposite ends.
Fulcrum
Give an example of a first class lever
See saw
Give an example of a second class lever.
Bottle opener
Give an example of a third class lever.
The arm of a person using a tennis racket to hit a ball
Explain how some using a tennis racket is an example of a third class lever
The shoulder is the fulcrum, the arm applies the effort, and the load, or the resistance, is the ball hitting the racket.
What class of lever is a nutcracker?
Class 2
What class of lever is a pair of tweezers?
Class 3
Which demonstrates a first class lever, a person using a crowbar to pry a rock out of a ground, or a person using a wheelbarrow? Why?
A person using a wheelbarrow because the fulcrum is the wheel, the effort is the handle, and the load is on top.
In science, work means ———
Force- pushing or pulling- in order to move an object a certain a certain distance
The formula to find how much work is done
Work = force x distance
What is a simple machine?
A tool made up of one or two parts
What is a compound machine?
A tool containing one or more simple machines among its parts
What are some examples of compound machines?
Cars, airplanes, elevators, staplers,
What are the six types of simple machines?
Lever Inclined plane Wedge Screw Wheel and axle Pulley
Explain how a wedge and a screw are related to the inclined plane.
A wedge is made up of two inclined planes that come to a point.
A screw is an inclined plane that is wrapped up in a spiral
What is a pulley?
A grooved wheel with a rope or chain around it
What is a fixed pulley?
- It stays in one position as the wheel spins.
- Lets you pull down on one end to lift up the load on the other end
What is a movable pulley?
- It is attached to the object being moved.
- As force is applied to the load, the pulley moves along with the load.
- Decreases the force you must apply, but the force you use is applied over a greater distance.
What is a block and tackle?
A system in which several pulleys can be used with the same rope.
Used to lift a very heavy load, such as a piano
A wheel and axle is made up of
A wheel with a rod joined at the wheel’s center
A wheel and axle can—–
Increase a force or increase the distance through which a force acts
Why is it that the amount of work done by a machine is less than the amount put into it?
Because of friction.
The more moving parts a machine has, the more work is lost to friction.
That’s why people who design machines try to reduce the amount of friction between the parts to make the machine more efficient
