Work and Power
Power
For a force to do work on an object, some of the force must act in the same____________as the object moves.
direction
When using a simple machine you can alter the _________ and _____________ but not the total work done.
force and distance
A device that changes a force
Machine
A simple machine that consists of two disks or cylinders, each with a different radius
Wheel and axle
The SI unit of power
Watt
Any part of a ____________that does not act in the direction of motion does no work on a object.
input force multiplied by the input distance is the input _______
Work
What is the work done by a lever that applies a 2N force over 5M?
10J
A v-shaped object whose sides are two inclined planes sloped towards each other
The product of force and distance
Work
If there is no__________________no work is done.
movement
What kind of simple machines are used in scissors
wedge and lever
Machines make work_______to do
easier
A rigid bar that is free to move around a fixed point
Lever
The SI unit of work
Joule
Formula for calculating work
work=force X distance
How does work remain the same but force decreases because of the use of a machine?
The distance increases
Machines change the size of a ________needed, the direction of a __________, or the distance over which a ___________ acts.
force
Pulley
The formula for power
P=w/t
When using SI units in the work formula, force is in _________and distance is in ____________
newtons;meters
the point on a lever where the bar pivots around
the fulcrum
What is the distance of the lever that applied 6J of work with a force of 3N?
2M
An inclined plane wrapped around a cylinder
Screw