Work and Power
Power
For a force to do work on an object, the force must act in the same____________as the object moves.
direction
Some machines change the direction exerted by the force. Give me an example.
a jack or a pulley
What is the formula for the MA of a wheel and axle?
radius of the wheel / radius of the axle
A simple machine made of 2 circular objects that are connected and turn together?
Wheel and axle
The unit for power
Watt
True or False: pushing a shopping cart around not doing work
True
The number of times a force applied on a machine is multiplied by the machine is called ...
Mechanical Advantage
What kind of a lever would a pair of pliers be?
first class lever
A v-shaped object which is made of 2 inclined planes connected back to back.
Wedge
What is the unit used to rate engines in our world today?
Horse Power
It takes 100 N to move an object 10 m. What is the amount of work being done on this object?
1000 J
Machines make work_______to do
easier
A machine that utilizes 2 or more simple machines is a ...
Compound machine
A rigid bar that is free to move around a fixed point
Lever
The unit for work
Joule
Formula for calculating work
work=force X distance
What do we call the comparison of output work to input work by a machine?
efficiency
What is the unit for mechanical advantage
There is no unit
Pulley
In order to do work, the object that has a force on it must _______________
move
When using units in the work formula, force is in _________and distance is in ____________
newtons;meters
What do we call a machine's MA without friction acting on it?
Ideal Mechanical Advantage or IMA
What is the MA formula for a lever?
effort arm divided by the resistance arm
An inclined plane wrapped around a cylinder
Screw