Power and Efficiency

Flashcards based on lecture notes about power, efficiency, and simple machines.

Work may be defined as the __.

The scalar product of the force applied and the displacement.

Work (W) = __

F * s * cos(theta)

Work is equal to __.

Change in energy.

Power is defined as __.

The rate of doing work.

The SI unit for power is the __.

Watt (W)

The SI unit for work is the __.

Joule (J)

1 kilowatt (kW) = __

1000 W

1 megawatt (MW) = __

1000000 W

The SI unit of work is __.

Joule (J)

The CGS unit of work is __.

erg

The British system unit of work is __.

foot-pound (ft-lb)

The SI unit of power is __.

watt (W)

The CGS system unit of power is __.

erg per second (ergs^-1)

The British system unit of power is __.

foot-pound per second (ft-lbs^-1)

The British engineering system unit of power is __.

horse power (hp)

1 horse-power (hp) = __.

550 ft-lbs

1 hp = __.

746 W

Power (P) = __ (in terms of force and velocity)

Fv

Power is equal to the __.

Product of force and velocity.

A simple machine is __.

A mechanical device that amplifies the magnitude of a force and changes its position.

The six simple machines are __.

Lever, wheel and axle, pulley, inclined plane, screw, and wedge.

Mechanical advantage = __.

Load / Effort

Mechanical advantage (MA) = __

load / effort

Power is __.

The rate at which work is done.

Work produces __.

Energy change

W = APE = __

mgh

If the work done is __ , the power is 1 watt.

1 joule in 1 second

1 W = 1 Js-1 = __

10^7 ergs/s

P = __

Fs/t

A simple machine __.

amplifies the magnitude of force

Simple machines are used to make work __.

Easier

Car engines and electric bulbs are specified according to their __.

power consumption.

If a man lifts an object to a certain height, the __ of object will change.

Potential energy

The rate of energy change is also important in __.

Power

W stands for the physical unit __.

Watt

Work may be defined as the __ of the force applied and the displacement.

Scalar Product

A simple machine __ the magnitude of a force and changes its position.

Amplifies

A simple Machine is a __ that amplifies the magnitude of a force and changes its position.

Mechanical device

A simple machine amplifies the __ of a force and changes its position.

Magnitude

Nowadays, machines are just __ of simpler machines.

combination

Power is a very important concept for __ works.

Engineering

The change in __ is equal to the work done on the object.

Potential energy

The unit for power is the __.

Watt

The unit for __ in SI units is the watt (W).

Power

1kW = __

103 W

1 MW= __

10^6 W

It is __ to consider the rate at which work is done.

useful

Whenever a force acting on an object produces __ work is done by the force.

movement

The rate of work(or) the rate of energy change is also __ in practice.

Important

Work is done only when an object moves under the influence of a __.

Force