1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help, New Physics Student!

  1. Jan 24, 2008 #1
    I am new to Physics and I need help on this problem

    A skater increases her speed uniformly from 2.0 meters per second to 7.0 meters per second over a distance of 12 meters. The magnitude of her acceleration as she travels this 12 meters is?

    A. 2.4 m/s squared
    B. 3.8 m/s squared
    C. 1.9 m/s squared
    D. 2.2 m/s squared

    Can you please give me an explanation of how to solve this since this seems pretty easy?

  2. jcsd
  3. Jan 24, 2008 #2


    User Avatar
    Homework Helper

    You must show some work in order to get help. Do you know your kinematic equations? You only need one equation to solve this. Can you explain what is confusing you?
  4. Jan 24, 2008 #3
    My teacher taught me a=v/t and I get the answer A but it says that I am wrong. But I don't have the T so I don't know what to do from then on.
  5. Jan 24, 2008 #4


    User Avatar
    Homework Helper

    I'm sure there are derivations of some other useful kinematic equations in your textbook (if you were given one). But what you can do is start with the definition of average acceleration

    [tex]a_{ave} = \frac{\Delta v}{\Delta t}[/tex]

    The displacement (distance) of the car will be the average velocity of the car multplied by the time interval [tex] \Delta t [/tex]

    So that is [tex]\Delta x = (\frac{v_o + v}{2}) \Delta t[/tex]

    So arrange this for [tex]\Delta t[/tex] and substituting it into your first equation will allow you to solve for a in terms of displacement.

    Does that make sense?

    See https://www.physicsforums.com/showpost.php?p=905663&postcount=2

    This site might help: http://hyperphysics.phy-astr.gsu.edu/hbase/mot.html#mot1
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Help, New Physics Student!