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

    9
    ReputationRep:
    Hi

    I;ve been trying to work out this question for about an hour and can't seem to get it right. I know the answer is C because I've checked the answers but can't seem to work out how to get to it and I really want to know.

    Its question number 2 on the picture

    Thank you in advance
    Matt
    Attached Images
     
    Offline

    8
    ReputationRep:
    I'm guessing you assumed he fired the arrow at an angle? If you assume he fires it vertically upwards (I guess because they normally make it clear if the object was fired/thrown or whatever at an angle) then you get the correct answer. Using v^2=u^2+2as with v=0, u=30 (you don't care about horizontal velocity since the arrow was fired vertically upwards), a=9.81 and s=? (remembering to add 1 to your value of s since it was fired from 1 metre above the ground).
    Offline

    18
    ReputationRep:
    (Original post by victoria98)
    I'm guessing you assumed he fired the arrow at an angle? If you assume he fires it vertically upwards (I guess because they normally make it clear if the object was fired/thrown or whatever at an angle) then you get the correct answer. Using v^2=u^2+2as with v=0, u=30 (you don't care about horizontal velocity since the arrow was fired vertically upwards), a=9.81 and s=? (remembering to add 1 to your value of s since it was fired from 1 metre above the ground).
    It's not that you're supposed to assume he fires it vertically. In the question he does fire it at an angle clearly because it has both horizontal and vertical components.

    The point of the question is to recognise that you only consider the vertical component and hence do a simple suvat calculation, adding 1m at the end
    Offline

    8
    ReputationRep:
    (Original post by Student403)
    It's not that you're supposed to assume he fires it vertically. In the question he does fire it at an angle clearly because it has both horizontal and vertical components.

    The point of the question is to recognise that you only consider the vertical component and hence do a simple suvat calculation, adding 1m at the end
    Ah yes that's right, my bad. That does make more sense. Either way the calculation is the same
    Offline

    18
    ReputationRep:
    (Original post by victoria98)
    Ah yes that's right, my bad. That does make more sense. Either way the calculation is the same
    Indeed the calculation is the same But the problem arises when people wrongly think they have the right understanding, and then get confused in other questions or the exam because they applied this misconception

    Anyway that was just rambling
    Offline

    8
    ReputationRep:
    (Original post by Student403)
    Indeed the calculation is the same But the problem arises when people wrongly think they have the right understanding, and then get confused in other questions or the exam because they applied this misconception

    Anyway that was just rambling
    I do get what you mean, and I remember I used to 'understand' projectile motion for G481 and then immediately after, I forgot most of the stuff (evidently) but I did get the marks on the question that came up in my exam. Should probably make sure I'm 100% sure on what I'm doing before I pass it on to someone else though.
    Offline

    18
    ReputationRep:
    (Original post by victoria98)
    I do get what you mean, and I remember I used to 'understand' projectile motion for G481 and then immediately after, I forgot most of the stuff (evidently) but I did get the marks on the question that came up in my exam. Should probably make sure I'm 100% sure on what I'm doing before I pass it on to someone also though.
    It will come with practice :yep:
    Offline

    8
    ReputationRep:
    (Original post by Student403)
    It will come with practice :yep:
    It's a good thing I only need an A for my firm choice (and projectile motion in A2 is not very common haha)
    Offline

    18
    ReputationRep:
    (Original post by victoria98)
    It's a good thing I only need an A for my firm choice (and projectile motion in A2 is not very common haha)
    Haha true
    • Thread Starter
    Offline

    9
    ReputationRep:
    Thanks guys victoria98 and Student403 I've got the answer now. I think I was looking too deeply into it
 
 
 
  • 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
    Would you like to hibernate through the winter months?
  • 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.