Vocab 1
A measure of power equal to one joule of work per second.
Watt
The rate at which work is done
Which simple machine has an inclined plane that moves?
Wedge
How much work is done when a vertical force acts on an object moving horizontally?
None
True or False?
The mechanical advantage of a pulley system depends upon the number of sections of rope.
True
SI unit of energy
Joule
Force exerted on an object that causes it to move
Work
Which simple machine consists of a slanted surface along which a force moves an object to a different elevation.
Inclined Plane
Doing work faster requires more ________?
Power
True or False?
Ideal Mechanical Advantage is calculated from work input and work output.
False: Efficiency
A common unit of power, equal to about 746 watt (neigh)
Horsepower
The ratio of output work to input work
Efficiency
Which simple machine consists of a bar that pivots at a fixed point called a fulcrum?
Lever
Because of _________, the work done by a machine is always less than the work done on the machine.
Friction
True or False?
If a machine has a mechanical advantage much larger than 1, its output much larger than its input force.
True
The pivot point of a lever
Fulcrum
The number of times a machine increases a force exerted on it
Mechanical Advantage
Which simple machine consists of a rope that fits into a groove in a wheel?
Pulley
What formula relates to work and power?
Work=Force x Distance
True or False?
A wheel and axle are like a pulley in which the fulcrum is located at the center of the two concentric rotating cylinders.
False: It's like a lever
A device that combines two or more simple machines
Compound Machine
A device that makes work easier
Machine
Which simple machine consists of two circular objects of different sizes; the wheel is the larger of the two circular objects?
Wheel and Axel
What is one change a machine can make to a force?
Size of force
the direction of the force
distance through which a force acts
Final Jeopardy:
A machine has an efficiency of 60%. What happens to 60% of the work put into the machine, and what happens to the other 40%?
60% of the work input becomes work output while the other 40% of work input is lost to friction.