Hey! Sign in to get help with your study questionsNew here? Join for free to post

M1 Projectiles

Announcements Posted on
Talking about ISA/EMPA specifics is against our guidelines - read more here 28-04-2016
  1. Offline

    ReputationRep:
    If I don't get part A correct, I'm screwed for the rest of the questions.

    Is it tan inverse 6/8 ?? ie 36.9 degrees? (3SF)

    Click image for larger version. 

Name:	IMG-20120506-00122.jpg 
Views:	57 
Size:	347.5 KB 
ID:	146081
  2. Offline

    ReputationRep:
    Where do you get the 8 from? Use toa.
  3. Offline

    ReputationRep:
    (Original post by Hopple)
    Where do you get the 8 from? Use toa.
    So its tan inverse 6/10?

    IDK but I put the velocity of 8 as part of the triangle then assumed 10 must have been the hyptonuse, so i thought 8 was the adjacent :|
  4. Offline

    ReputationRep:
    (Original post by MSI_10)
    So its tan inverse 6/10?
    Yeah, that's it.
  5. Offline

    ReputationRep:
    yes tanα is 6/10
  6. Offline

    ReputationRep:
    (Original post by Hopple)
    Yeah, that's it.
    Aight thanks.

    Am I starting part b probably; to get time, first need to use S. Do I use 6 or 10..?

    Then SUVAT (S=ut+o.5at^2) use quadratic formula to get t?
  7. Offline

    ReputationRep:
    (Original post by MSI_10)
    Aight thanks.

    Am I starting part b probably; to get time, first need to use S. Do I use 6 or 10..?

    Then SUVAT (S=ut+o.5at^2) use quadratic formula to get t?
    For part b, are you looking at vertical or horizontal motion (or both)? And yes, that suvat equation will do.
  8. Offline

    ReputationRep:
    (Original post by Hopple)
    For part b, are you looking at vertical or horizontal motion (or both)? And yes, that suvat equation will do.
    I did this..
    S=-6
    a=-9.8
    U=8sin31..

    -6=8sin31t-4.9t^2
    -4.9^2+8sin31t+6=0
    got t=1.60 or t=-0.763

    Answer t=1.60..?
  9. Offline

    ReputationRep:
    (Original post by MSI_10)
    I did this..
    S=-6
    a=-9.8
    U=8sin31..

    -6=8sin31t-4.9t^2
    -4.9^2+8sin31t+6=0
    got t=1.60 or t=-0.763

    Answer t=1.60..?
    Make sure you're measuring everything in the same direction.
  10. Offline

    ReputationRep:
    (Original post by Hopple)
    Make sure you're measuring everything in the same direction.
    :\
  11. Offline

    ReputationRep:
    (Original post by MSI_10)
    :\
    Even though everything's going downwards, you've made displacement and acceleration be in the opposite direction to initial velocity.
  12. Offline

    ReputationRep:
    (Original post by Hopple)
    Even though everything's going downwards, you've made displacement and acceleration be in the opposite direction to initial velocity.
    Oh that's what you meant, yeah i get what you mean now thanks

    So t=0.763
  13. Offline

    ReputationRep:
    Hmm, can anyone check if im doing part c correctly.

    It's asking for distance.. do I use the time obtained from part b, use S=ut+1/2at^2 but use 8cos31 for u instead of 8sin31..?
  14. Offline

    ReputationRep:
    (Original post by MSI_10)
    Hmm, can anyone check if im doing part c correctly.

    It's asking for distance.. do I use the time obtained from part b, use S=ut+1/2at^2 but use 8cos31 for u instead of 8sin31..?
    Yes, but remember there are no forces acting horizontally here.
  15. Offline

    ReputationRep:
    (Original post by finality)
    Yes, but remember there are no forces acting horizontally here.

    Alright so I used 8sin31
    I get the answer as 6m. Something tell's me this aint right; it seems to high :\

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: May 6, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR

How to predict exam questions

No crystal ball required

Poll
How will you be voting in the EU referendum?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

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