Power, Physics

Assignment Help:

Power:

The rate of doing work is called power, and it is defined as the work done in unit time.  As a formula, this would be:

power = work done/time Taken

 Power is expressed in several different units, such as the watt, ergs per second, and foot-pounds per second.  The most common unit of power in general use in the United States is the horsepower.  One horsepower (hp) is equal to 550 ft-lb's or 33000 ft-1b/min.  In the metric system the unit of power is the watt (W) or the kilowatt (kW).  One hp is equal to 746 watts; and 1 kW = 1.34 hp.

Example:

To compute the power necessary to raise an elevator containing 10 persons a distance of 100 ft in 5 s (assuming the loaded elevator weighs 2500 lb), proceed as follows:

Power = work done/Time Taken        = 2500 x 100/5                 = 50,000 ft-lb's/sec

 

    Since 1hp = 550 ft-lb's/sec then required hp = 50,000/550

      = 90.9 hp (67.81 kw assuming no friction losses)

 

 


Related Discussions:- Power

Does the path of the current induced to flow in the coil, A bar magnet is o...

A bar magnet is overhanging vertically above a closed coil of wire. The bar magnet is unconfined. It remainder vertical as it come near the coil falls straight through the coil and

Types of motion, which circular path in any time in any mation

which circular path in any time in any mation

Magnetic effects of electric current, How to find out neutral point ? What...

How to find out neutral point ? What all things we require to equate or form a equation to find the neutral poind and how to do it?

Speed of light in vacuo, Speed of light (in vacuo); c The speed on whic...

Speed of light (in vacuo); c The speed on which electromagnetic radiation propagates within a vacuum; it is described as 299 792 458 m/s.

Which material has the highest melting point, Which of the following materi...

Which of the following material has the highest melting point (A) Copper. (B) Aluminium. (C) Tungsten. (D) Gold. Ans: Tungsten has the highest melting point.

Young two slit interference experiment, If Young' two slit interference exp...

If Young' two slit interference experiment is done with white light what could be seen?

Bead sliding on wire, Bead Sliding on Wire A vertical hoop supports a w...

Bead Sliding on Wire A vertical hoop supports a wire which is attached from the top of the hoop to any other point. Illustrate that the time required for a frictionless bead to

rectilinear scanner, Nuclear medicine imagining devices : Imagining ,or p...

Nuclear medicine imagining devices : Imagining ,or producing pictures of the distribution of the radioactivity is the most important aspect of nuclear medicine. Rectilinear s

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd