Results 1 to 11 of 11

Math Help - Physics Help

  1. #1
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Physics Help

    A migrating bird is initially flying south at 7 m/s. To avoid hitting a high-rise building, the bird veers and changes its velocity to 6 m/s east over a period of 2 s. What is the bird's average acceleration (magnitude and direction) during this 2 s interval?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member ILikeSerena's Avatar
    Joined
    Dec 2011
    Posts
    733
    Thanks
    121

    Re: Physics Help

    Quote Originally Posted by Louisana1 View Post
    A migrating bird is initially flying south at 7 m/s. To avoid hitting a high-rise building, the bird veers and changes its velocity to 6 m/s east over a period of 2 s. What is the bird's average acceleration (magnitude and direction) during this 2 s interval?
    Hi Louisana1!

    Can you write the initial velocity as a vector?
    And the final velocity as a vector as well?

    If so, can you fill them in the formula for average accelation?
    That formula is:
    \vec a_{average} = {1 \over \Delta t} (\vec v_{final} - \vec v_{initial})
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Re: Physics Help

    -1/2
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426

    Re: Physics Help

    subtracting vectors ...

    i = unit vector in positive x-direction (East)

    j = unit vector in positive y-direction (North)

    v_0 = -7j

    v_f = 6i

    \Delta v = v_f - v_0 = 6i + 7j

    a = \frac{\Delta v}{\Delta t} = \frac{6i + 7j}{2} = 3i +3.5j

    |a| = \sqrt{3^2 + 3.5^2} = 4.6 \, m/s^2

    direction of the average acceleration vector ...

    \theta = \arctan\left(\frac{3.5}{3}\right) = 49^\circ
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Re: Physics Help

    not sure how you got the 49
    Thanks skeeter
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426

    Re: Physics Help

    the inverse tangent function on my calculator ...
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Re: Physics Help

    It said it was wrong on my online homework
    Follow Math Help Forum on Facebook and Google+

  8. #8
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426

    Re: Physics Help

    Quote Originally Posted by Louisana1 View Post
    It said it was wrong on my online homework
    the angle is rounded to the nearest degree ... what is the criteria for entering answers as far as decimal places? If it's significant figures, it should be 50 degrees.
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Re: Physics Help

    still wrong I'm trying to figure it out too
    Follow Math Help Forum on Facebook and Google+

  10. #10
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,298
    Thanks
    1276

    Re: Physics Help

    What was wrong? What answer did you give?
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Member
    Joined
    Aug 2012
    From
    new orleans
    Posts
    131
    Thanks
    1

    Re: Physics Help

    the 49 degrees is incorrect the other part is right
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Got a physics question or interested in physics?
    Posted in the Math Topics Forum
    Replies: 16
    Last Post: February 3rd 2014, 01:56 AM
  2. physics 2
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: October 25th 2009, 01:24 AM
  3. how do solve quantum physics or physics equations
    Posted in the Advanced Applied Math Forum
    Replies: 2
    Last Post: March 26th 2008, 04:33 AM
  4. physics
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: October 8th 2007, 03:36 AM
  5. physics, acceleration, physics problem
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: September 29th 2007, 03:50 AM

Search Tags


/mathhelpforum @mathhelpforum