Home > Math Group > Question and Answer

Math Group

Question:

hrrjack
hrrjack
Student
College - Freshman

One horsepower is equal to 746 watts. An automobile engine delivers 53.7 hp.

How much time will it take for the engine to do 5.50 x 10 to the fifth power J of work? Answer in units of s.

Rate question:

Posted by hrrjack on Wednesday November 4, 2009 at 5:50 AM and tagged with energy, math, power.

Answers:

  1. krishna-agrawala
    krishna-agrawala Teacher
    Graduate School

    eNotes Editor

    Given:

    Power = 53.7 hp = 53.7*746 W = 40060.2 W

    Work done = 5.50 x 10^5 J

    We have to find the time taken to do the work

    Time taken to do the work is given by formula:

    Time = Work/Power = (5.50 x 10^5)/40060.2 = 13.7293 s

    Answer:

    Engine will take 13.7293 s to do the work.

    Rate answer:

    Posted by krishna-agrawala on Wednesday November 4, 2009 at 6:53 AM

  2. neela
    neela Teacher
    Graduate School

    eNotes Editor

    The generation of power in automobile engine = 53.7hp=53.7*746 watts/s

    The required work to be done is 5.50*10^5 J.

    Let x be the time in seconds for the engine to work 5.5010^5 J

    Therefore Power* x= work done

    53.7*746 w  *x =5.50*10^5 J

    x= 5.50*10^5/(53.7*746)=13.7293 seconds

    Rate answer:

    Posted by neela on Wednesday November 4, 2009 at 8:08 AM