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Find the angle and the velocity of two cars after collision

  1. Nov 11, 2009 #1
    1. The problem statement, all variables and given/known data

    Two cars are driving on an icy parking lot, searching for a free parking space. The first car has a mass m1= 1000 kg and traveling at a speed of 20 km/h, the second car has a mass of m2= 800 kg and drives perpendicular to the direction of the first car at a speed of 15 km/h. They are not aware of each other and crash, so that their cars slide together at an angle θ along previous direction of the first car.
    - With what velocity will the two cars be moving immediately after the collision?
    - Find the angle at which the two cars start moving?

    http://www.slide.com/s/kqikbbPm1j8EewZiTRju4CCgaHODnfDF?referrer=hlnk [Broken]

    2. Relevant equations

    p= mv
    tan= opp/adj

    3. The attempt at a solution

    First part: With what velocity will the two cars be moving immediately after the collision?

    x-direction: m(1)v(1) + 0= (m(1) + m(2))v(x) → v(x)= m(1)v(1) / (m(1) + m(2))
    v(x)= 11.11 km/h
    y-direction: 0 + m(2)v(2)= (m(1) + m(2))v(y) → v(y)= m(2)v(2) / (m(1) + m(2))
    v(y)= 6.66 km/h

    v²= v(x)² + v(y)²
    v= 12.95 km/h

    Second part: Find the angle at which the two cars start moving?

    tan θ= v(y) / v(x)= [m(2)v(2) / (m(1) + m(2))] / [m(1)v(1) / (m(1) + m(2))]= m(2)v(2) / m(2)v(2)= 0.6
    θ= 30.96 º

    I really need to know if may calculations are correct.
    Thank you for helping!:smile:
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 11, 2009 #2

    ideasrule

    User Avatar
    Homework Helper

    Yes, they're correct.
     
  4. Nov 11, 2009 #3
    Thank you :smile: !
     
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