Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hey could someone help me with this?

    A stone is catapulted from ground level at an angle of 35degrees to the horizontal. If the stone hits the ground 25m from its point of projection. Find its speed of release and the time it is in the air.

    Help will be appreciated, thanks
    Offline

    13
    ReputationRep:
    Use the equations ?
    Offline

    16
    ReputationRep:
    this is your third projectiles question thread... stop trying to get people to do your homework for you.
    • Thread Starter
    Offline

    0
    ReputationRep:
    i have two unknowns in all the equations
    Offline

    13
    ReputationRep:
    Think abt the vertical displacement.
    Offline

    13
    ReputationRep:
    When it hits the ground back, the vertical displacement is : __________________________
    • Thread Starter
    Offline

    0
    ReputationRep:
    zero
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by didgeridoo12uk)
    this is your third projectiles question thread... stop trying to get people to do your homework for you.
    well, am i not aloud to ask for help?, and also if u notice in only 1 of them someone gives me the actual answer, which i then reconfirmed. Sorry if im being rude, but im not
    Offline

    13
    ReputationRep:
    Exactly.
    Offline

    13
    ReputationRep:
    Think about using

    \large V = \large U + \small a \small t

    Connected with the vertical displacement, and the fact that at the maximum height  \large V = 0

    The time for this will be half the overall time
    Offline

    16
    ReputationRep:
    (Original post by hassantahir)
    well, am i not aloud to ask for help?, and also if u notice in only 1 of them someone gives me the actual answer, which i then reconfirmed. Sorry if im being rude, but im not
    you can ask for help, but show all your working so far so we can see where you're going wrong
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by CookieGhoul)
    Think about using

    \large V = \large U + \small a \small t

    Connected with the vertical displacement, and the fact that at the maximum height  \large V = 0

    The time for this will be half the overall time
    I still have two unknowns, no? U and T
    • Thread Starter
    Offline

    0
    ReputationRep:
    So far i have got : t= 25/(Ucos35) i dont know if that is right though
    Offline

    2
    ReputationRep:
    (Original post by hassantahir)
    So far i have got : t= 25/(Ucos35) i dont know if that is right though
    Yes now work out t using the vertical displacement and use simultaneous equations to work out the initial velocity and in turn t.
    Offline

    13
    ReputationRep:
    (Original post by hassantahir)
    So far i have got : t= 25/(Ucos35) i dont know if that is right though

    Yea thats for the horizontal displacement. Now work the vertical displacement
    Offline

    13
    ReputationRep:
    How about this:

     \large V = \large U + \small a \small t



     0 = \large U \sin 35 + (-10)(\frac {\small t}{2})


    How about now ?
    • Thread Starter
    Offline

    0
    ReputationRep:
    t=Usin35/4.9
    Offline

    13
    ReputationRep:
    Right. Can you solve it now ?
    Offline

    2
    ReputationRep:
    (Original post by hassantahir)
    t=Usin35/4.9
    yep that's what I got, now substitute for t and solve for U
    • Thread Starter
    Offline

    0
    ReputationRep:
    25/Ucos35=Usin35/4.9
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 14, 2011

University open days

  1. University of Bradford
    University-wide Postgraduate
    Wed, 25 Jul '18
  2. University of Buckingham
    Psychology Taster Tutorial Undergraduate
    Wed, 25 Jul '18
  3. Bournemouth University
    Clearing Campus Visit Undergraduate
    Wed, 1 Aug '18
Poll
How are you feeling in the run-up to Results Day 2018?
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

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.