Hey there! Sign in to join this conversationNew here? Join for free

Physics question? (suvat) UKCAT Watch

Announcements
    • Thread Starter
    Offline

    12
    ReputationRep:
    Explain to me how is accelerating from rest to 60mph in 6s is equivalent to moving at 30mph for 6s????

    The QR on the UKCAT mock 1 is unbelievably hard!!
    • Thread Starter
    Offline

    12
    ReputationRep:
    IMG
    Attached Images
     
    Offline

    10
    ReputationRep:
    (Original post by bobwibbles)
    Explain to me how is accelerating from rest to 60mph in 6s is equivalent to moving at 30mph for 6s????

    The QR on the UKCAT mock 1 is unbelievably hard!!
    If you draw a graph of speed versus time for accelerating from rest to 60mph in 6s, you would get a straight line pass through the origin to 60 mph. The area under this graph is the distance travelled by the object in 6 s.

    It is found by calculating the area of a triangle:

     \frac{1}{2} \times 60 \text{ mph} \times 6 \text{ s}

    Before computing the whole thing do a bit of simplification,

     \frac{1}{2} \times 60 \text{ mph} \times 6 \text{ s} = 30 \text{ mph} \times 6 \text{ s}

    Actually, 30 mph is the average speed for the journey of accelerating from rest to 60mph in 6s.
    • Thread Starter
    Offline

    12
    ReputationRep:
    (Original post by Eimmanuel)
    If you draw a graph of speed versus time for accelerating from rest to 60mph in 6s, you would get a straight line pass through the origin to 60 mph. The area under this graph is the distance travelled by the object in 6 s.

    It is found by calculating the area of a triangle:

     \frac{1}{2} \times 60 \text{ mph} \times 6 \text{ s}

    Before computing the whole thing do a bit of simplification,

     \frac{1}{2} \times 60 \text{ mph} \times 6 \text{ s} = 30 \text{ mph} \times 6 \text{ s}

    Actually, 30 mph is the average speed for the journey of accelerating from rest to 60mph in 6s.
    Ah makes sense. Thank you!
 
 
 
  • 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
    Break up or unrequited love?
  • 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

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