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

Explain range of projectile, RANGE OF PROJECTILE:  "It is the horizonta...

RANGE OF PROJECTILE:  "It is the horizontal distance covered by the projectile from the point of projection to the point where it returns to its level of projection".

Give the graphical representation of plane polarized light, Give the graphi...

Give the graphical representation of the end on view of plane polarized light and unpolarized light.

Find the value of g by free fall method, initial position time the vibra...

initial position time the vibration mean time time period of the bob t time

Magnetometer, discussion for magnetometer experiment

discussion for magnetometer experiment

Evaluate the deepest he could have been, In a movie, Tarzan evades his capt...

In a movie, Tarzan evades his captors by hiding underwater for many minutes while breathing through a long , thin reed . Assuming the maximum pressure difference his lungs can mana

Experiment on thermo electric thermometers, what are the advantages of usi...

what are the advantages of using the thermo-electric thermometer over the mecury glass thermometer?

Polarisation of light, Light propagates as transverse EM rays. The magnitud...

Light propagates as transverse EM rays. The magnitude of electric field is much larger as compared to magnitude of magnetic field. We generally prefer to define light as electric f

Fermi paradox, Fermi paradox (E. Fermi): E. Fermi's conjecture, simpli...

Fermi paradox (E. Fermi): E. Fermi's conjecture, simplified along phrase, "Where are they?" questioning that if the Galaxy is filled along with technological and intelligent c

Advantages of a.c. transmission of power, Advantages of A.C. transmission o...

Advantages of A.C. transmission of power 1. The power can be produced at high voltages. 2. The maintenance of a.c. sub-stations is simple and cheaper. 3. The a.c. voltage

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