Work and Machines 1
What is the formula for work?
Work = Force x Distance
Why do your arms do no work if you carry 50 books across a room?
Because your legs are causing the movement, not your arms.
What is a Kinetic Energy?
What is work?
Force applied through a distance
What is a compound machine?
Combination of two or more machines
What are the proper units/labels for the work equation?
Work = Joules
Force = Newtons
Distance = Meters
When does work occur?
You push a book, hitting a baseball.
What is Potential Energy?
Energy that is stored due to the interactions between objects
What is a Machine?
Device that changes the force or increases the motion from work
Machine that does work with only one movement of the machine
You push a refrigerator with a horizontal force of 100N. If you move the refrigerator a distance of 5 meters while you are pushing, how much work do you do?
100 Newtons x 5 meters = 500 Joules of work
What is an example of a compound machine?
Bike, scissors, computer, etc.
What is Mechanical Advantage?
Ratio of output force to input force
What is Energy?
The ability to cause change?
Energy cannot be created nor destroyed
Charlie does 750 Joules of work carrying a box from one room to another. IF charlie traveled a distance of 15 meters carrying the box, how large was the average force Charlie exerted to carry the box?
750Joules/15 meters = 50 Newtons
Kyle exerts a force of 75 Newtons while mowing the lawn. If Kyle did 550 joules of work, what was the total distance Kyle must have traveled?
550 Joules/ 75 Newtons = 7.33 meters
What is Power?
The rate at which energy is conveted?
What is Chemical Potential Energy?
Energy that is stored due to chemical bonds
What is Gravitational Potential Energy?
Energy due to the gravitational forces between objects
When do you do the most work?
When you push or move an object in the same direction it is moving already.
What are the 6 types of simple machines?
Pulley, Lever, Wheel and Axle, Wedge, Inclined Plane, and Screw
What is Elastic Potential Energy?
Energy that is stored by compressing, stretching, or bending an object?
What is a System?
Anything around which you can imagine a boundary
What is Mechanical Energy?
The sum of the kinetic energy and potential energy of the objects in a system