Results 1 to 20 of 20
  1. #1
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Physics Help

    1.
    A rubber ball weighs 49N
    a. what is the mass of the ball?
    b. what is the acceleration of the ball if an upward force of 69N is applied.

    I know that part a is 5kg, but I got stumbled on part b. Could someone please offer assistance and show necessary work.
     
         

  2. #2
    Wangy's Oreo Yasuko Sayomi's Avatar
    Status
    Yasuko Sayomi is offline
    Gender
    Join Date
    Sep 2012
    Location
    The second dimension to the left if you see Burger King you went too far
    Posts
    3,026
    Post Thanks / Like
    ***************
     

    Re: Physics Help

    You are trying to have Naruto Base do your homework? Wow...
     
         

  3. #3
    Senior Member Yusuke Urameshi's Avatar
    Status
    Yusuke Urameshi is offline
    Gender
    Join Date
    May 2012
    Location
    Hanging Neck Island
    Posts
    7,040
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Is this HS or college? If its High School, then I by-passed that for Chemistry.
     
         

  4. #4
    Writing time~ Netsui's Avatar
    Status
    Netsui is offline
    Gender
    Join Date
    Jan 2012
    Location
    Heat Haze
    Posts
    5,581
    Post Thanks / Like
    Writer in Training! I have so
    much I want to write, but
    there's not enough hours in
    the day.
     



    Re: Physics Help

    I could be wrong, but I believe the equation for acceleration is F/M, which would be 69/5. 69/5 = 13.8

    F is the force that is applied onto the mass, and you got the mass from Part A.
     
         

  5. #5
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by Yasuko Sayomi View Post
    You are trying to have Naruto Base do your homework? Wow...
    It's not homework moron, I'm just trying to understand the concept. If I wanted you to do my homework why would I only post one question? Use common sense before you spurt nonsense.
     
         

  6. #6
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    That's what I got at first but then I remember the teacher saying it was wrong lol.
     
         

  7. #7
    Senior Member Drakengard's Avatar
    Status
    Drakengard is offline
    Gender
    Join Date
    Feb 2012
    Posts
    4,225
    Post Thanks / Like
    HashiramaWankLord... return
    and save us all!
     

    Re: Physics Help

    Well if I'm right.. you have to find the net force of the object. Since 69N is applied upward, and 49N is applied downwards, that leaves 20N upward as your final result. Force = mass x acceleration.. SO 20N = 5kg x acceleration. That should be 4 m/s^2 upwards in the end if I'm correct. Get different answers though since I'm not confident at this type of stuff.
     
         

  8. #8
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    HS, took AP environmental freshmen year, then Chemistry, and here junior year taking Physics H
     
         

  9. #9
    Evil Boy Genius Jack Spicer's Avatar
    Status
    Jack Spicer is offline
    Gender
    Join Date
    Apr 2011
    Location
    DWMA
    Posts
    17,514
    Post Thanks / Like
    #panneverfails
     



    Re: Physics Help


     
         

  10. #10
    Mikasa es mi casa . Ackerman-'s Avatar
    Status
    Ackerman- is offline
    Gender
    Join Date
    Aug 2012
    Location
    With Mikasa.Esdeath.MichelleK.
    Posts
    28,312
    Post Thanks / Like
    Attack on Titan.Akame Ga
    Kill.Coppelion.Terra
    Formars.Tokyo
    Ghoul:Re/Favorite on-going
    mangas.
     

    Re: Physics Help

    sorry bro physics suck , cant help
     
         

  11. #11
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by Drakengard View Post
    Well if I'm right.. you have to find the net force of the object. Since 69N is applied upward, and 49N is applied downwards, that leaves 20N upward as your final result. Force = mass x acceleration.. SO 20N = 5kg x acceleration. That should be 4 m/s^2 upwards in the end if I'm correct. Get different answers though since I'm not confident at this type of stuff.
    I think your right that my second answer I came up with. I'm just debating which one is right 13.8 or 4
     
         

  12. #12
    Member whoami28's Avatar
    Status
    whoami28 is offline
    Gender
    Join Date
    Jun 2010
    Posts
    182
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    It's 4. Force = Mass * Acceleration. Therefore to find Acceleration it is Force/Mass. Plug and chug you get A = (69N-49N)/5kg. A = 4m/s^2
     
         

  13. #13
    Blitzking balla69's Avatar
    Status
    balla69 is offline
    Gender
    Join Date
    Apr 2011
    Location
    New Zealand
    Posts
    78
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    It's 4m/s^2 upwards. Drakengard is 100% right in his method.
     
         

  14. #14
    Academy Student
    Status
    theownerss is offline
    Gender
    Join Date
    Oct 2012
    Posts
    6
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    thanks for everyones responses.
     
         

  15. #15
    Member
    Status
    Iruka is offline
    Gender
    Join Date
    May 2011
    Posts
    608
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by theownerss View Post
    1.
    A rubber ball weighs 49N
    a. what is the mass of the ball?
    b. what is the acceleration of the ball if an upward force of 69N is applied.

    I know that part a is 5kg, but I got stumbled on part b. Could someone please offer assistance and show necessary work.
    Considering Newton's second law: F = ma

    For part a. we treat a as the downward acceleration due to gravity.

    F = ma
    49 = m * 9.8
    m = 5.0-kg


    For part b. we consider the net force acting on the ball. It has an upward force of 69-N but this is partially countered by the present weight force of 49-N.

    F = ma
    FNET = ma
    69 - 49 = 5.0 * a
    a = 4.0-ms-2
     
         

  16. #16
    Kuroh's Avatar
    Status
    Kuroh is offline
    Gender
    Join Date
    May 2012
    Location
    FL
    Posts
    13,707
    Post Thanks / Like
    Defy your own limits, they
    thought that I would die but I
    survived off spinach Macho
    man, Popeye did it And I know
    you lookin down so, Pop I did
    it
     



    Re: Physics Help

    Quote Originally Posted by Drakengard View Post
    Well if I'm right.. you have to find the net force of the object. Since 69N is applied upward, and 49N is applied downwards, that leaves 20N upward as your final result. Force = mass x acceleration.. SO 20N = 5kg x acceleration. That should be 4 m/s^2 upwards in the end if I'm correct. Get different answers though since I'm not confident at this type of stuff.
    this is right
     
         

  17. #17
    One Piece <3 Yo Momma San's Avatar
    Status
    Yo Momma San is offline
    Gender
    Join Date
    May 2011
    Location
    East Blue
    Posts
    11,729
    Post Thanks / Like
    ...Giggity
     

    Re: Physics Help

    ...
    This is so soft but I haven't taken any sciences this year and I forgot
     
         

  18. #18
    Member Fujin's Avatar
    Status
    Fujin is offline
    Gender
    Join Date
    Feb 2012
    Location
    Down Under
    Posts
    55
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by Iruka View Post
    Considering Newton's second law: F = ma

    For part a. we treat a as the downward acceleration due to gravity.

    F = ma
    49 = m * 9.8
    m = 5.0-kg


    For part b. we consider the net force acting on the ball. It has an upward force of 69-N but this is partially countered by the present weight force of 49-N.

    F = ma
    FNET = ma
    69 - 49 = 5.0 * a
    a = 4.0-ms-2
    You're forgetting the negative sign. Depending on which direction you take as positive.
     
         

  19. #19
    Member
    Status
    Iruka is offline
    Gender
    Join Date
    May 2011
    Posts
    608
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by Fujin View Post
    You're forgetting the negative sign. Depending on which direction you take as positive.
    The first part was in regard to weight force so I took the downward direction as positive, that's why I neglected a negative sign for the force and the acceleration. They would cancel to give a positive mass regardless.

    The second part was an upward acceleration. I took the upward direction as positive because it would result in a net force which was non-negative. It may be more consistent to keep the positive direction the same but I just really wanted to avoid negative values so that I didn't accidentally drop a negative.
     
         

  20. #20
    Member Fujin's Avatar
    Status
    Fujin is offline
    Gender
    Join Date
    Feb 2012
    Location
    Down Under
    Posts
    55
    Post Thanks / Like
    This user has no status.
     

    Re: Physics Help

    Quote Originally Posted by Iruka View Post
    The first part was in regard to weight force so I took the downward direction as positive, that's why I neglected a negative sign for the force and the acceleration. They would cancel to give a positive mass regardless.

    The second part was an upward acceleration. I took the upward direction as positive because it would result in a net force which was non-negative. It may be more consistent to keep the positive direction the same but I just really wanted to avoid negative values so that I didn't accidentally drop a negative.
    I thought as much. I just thought I would mention it, because it wouldn't be the first time someone has lost marks for not having the correct sign.
     
         

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •