1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Power of the Crane

  1. Jun 5, 2013 #1

    adjacent

    User Avatar
    Gold Member

    This crane is lifting a 1Kg Box.Gravity exerts 10N on this.The crane uses 11N on lifting the box-That means the box is accelerating at 1m/s2.This also means it travels more and more distance in one sec as it rise(because of acceleration).This means that the work done by lifting the box also increase as the box rise ,in a second(As the resultant force is 1N and the rate of distance increasing increases with time)It follows that the power of the crane in changing.
    But when calculating power ,we generally do not account for this.Why?
     

    Attached Files:

  2. jcsd
  3. Jun 5, 2013 #2

    PhanthomJay

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Sometimes the word 'power' and 'average' power are used to describe the same thing, but in actuality, there are 2 definitions for power, average power and instantaneous power. When the speed is constant, they are the same. When acceleration is involved, they are not.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Power of the Crane
  1. Work and power (Replies: 14)

Loading...