Physical Science Flashcards
What does a weight lifter that is holding bar bells above his head have to do in order to do work
Put it down
The rate that work is done is called
Power
The unit used for power is
Watts (w)
Work and energy is measured in
Jules (J)
A device that makes work easier is
A machine
Amount by which a machine multiplies the effort force. ——– The ratio of resistance force to effort force
Mechanical advantage
The force u apply to a machine
Effort (E)
The force applied by the machine
Resistance (r)
A machine that changes only the direction of the force has a mechanical advantage of
One
A measure of how much work is put into a machine that is turned into useful works is
Efficiency
Work output of a machine divided by the work input
Efficiency
The work output of a machine is always —— than the work input of the machine
Less
A device that does work with just one movement is
A simple machine
A bar that is free to pivot about a fixed point
Lever
A lever with a mechanical advantage greater than one is increase —-
Force
A grooved wheel with a rope, chain, or cable running along the groove —–
Pullay
A fixed pulley makes a block easier to lift by changing —– of the force needed to lift it
Direction
Am arrangement of pulleys designed to reduce effort force is a
Black and pulley system
A movable pulley —- the effort force
Decreased
A simple machine consist of a shaft or axel attached to the center of a large wheel so they rotate together—
Wheel and axel
A slanted surface used to raise an object
Inclined plane
An inclines plane wrapped around a cylindrical post
Screw
An inclined plane with one or two sloping sides
Wedges
Two or more simple machines working together are
Complex
—- is the transfer of energy that occurs when a force makes an object move in the direction of the force
Work
