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
The distance the input force acts through
Input 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.
The work done by the input force acting through the input distance
Work input
The distance the output force is exerted through
Output distance
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
The force that is exerted by a machine
Output force
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
The output force multiplied by the output distance
Work output
Machines change the size of a ________needed, the direction of a force, or the distance over which a force acts.
force
Pulley
Is equal to about 746 watts
Horsepower
When using SI units in the work formula, force is in _________and distance is in ____________
newtons;meters
The force you exert on a machine
Input force
The force that is exerted by a machine
Output force
An inclined plane wrapped around a cylinder
Screw