Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    7
    ReputationRep:
    A bus of mass 8 tonnes is driven up a hill on a straight road. On one part of the hill, the power of the driving

    force on the bus is constant at 20 kW for one minute.

    (i)
    Calculate how much work is done by the driving force in this time.
    [2]


    During this minute the speed of the bus increases from 8 m s–1 to 12 m s–1 and, in addition to the work done against gravity, 125000 J of work is done against the resistance to motion of the bus parallel to the slope.

    (ii)
    Calculate the change in the kinetic energy of the bus.
    [3]

    (iii)
    Calculate the vertical displacement of the bus

    Hi, just need some help on part 3 of this question
    The answers to the first two parts are 1,200,000J and 320000J increase
    • Thread Starter
    Offline

    7
    ReputationRep:
    any help
    Offline

    19
    ReputationRep:
    (Original post by mathsexam2013)
    any help
    KEA + PEA +WORKin - WORKout = KEB + PEB
    • Thread Starter
    Offline

    7
    ReputationRep:
    yes, but how do you work out PE with the information theyve given
    Offline

    19
    ReputationRep:
    (Original post by mathsexam2013)
    yes, but how do you work out PE with the information theyve given
    You rearrange the equation I gave you to PEB - PEA = ... the rest onto the other side ...
    the "right hand side quantities" are all known

    thus difference in PE can be found

    So mgh = ....


    I think the question merely asks for vertical displacement h
    • Thread Starter
    Offline

    7
    ReputationRep:
    (Original post by TeeEm)
    You rearrange the equation I gave you to PEB - PEA = ... the rest onto the other side ...
    the "right hand side quantities" are all known

    thus difference in PE can be found

    So mgh = ....


    I think the question merely asks for vertical displacement h
    yep, got it thanks
    Offline

    19
    ReputationRep:
    (Original post by mathsexam2013)
    yep, got it thanks

    my pleasure
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Has a teacher ever helped you cheat?
    Useful resources

    Make your revision easier

    Maths

    Maths Forum posting guidelines

    Not sure where to post? Read the updated guidelines here

    Equations

    How to use LaTex

    Writing equations the easy way

    Student revising

    Study habits of A* students

    Top tips from students who have already aced their exams

    Study Planner

    Create your own Study Planner

    Never miss a deadline again

    Polling station sign

    Thinking about a maths degree?

    Chat with other maths applicants

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Write a reply...
    Reply
    Hide
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.