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!

F=MA + Average Acceleration etc.

  1. Dec 2, 2009 #1
    1. The problem statement, all variables and given/known data

    A. A Volkswagen Rabbit has a mass of 1090 Kg and can go from 0mi/hour to 65 mi/hour in 12.0 seconds with an average acceleartion of 2.42 m/s^2. Disregarding friction, what force must the engine be producing?

    B.
    Disregarding friction, how much mass would need to be removed from the car above if it were to make the same velocity change in only 10.0 seconds with an average acceleration of 2.90m/s^2.


    2. Relevant equations
    f=ma



    3. The attempt at a solution

    a.f=ma
    f=(1090 kg) (2.42m/s^2)
    f=2640N

    okay I get a but do not understand B. How can the average acceleration be 2.42 m/s^2 when 0mi/hr to 65 mi/hour in 12.0 seconds when it is actually 5.41 m/s^2. Help is needed in finishing the problem then...

    thank you.
     
  2. jcsd
  3. Dec 2, 2009 #2

    Oddbio

    User Avatar
    Gold Member

    In part B you are going to use the force you found in part A, NOT the acceleration.
    So if you have the same force, but less mass do you think the car can get up to the same speed in more or less time?
     
  4. Dec 2, 2009 #3


    65 mi/hr = 29 m/s

    B.
    F = 2640 N
    a = 2.90 m/s^2
    F = ma

    Solve for m. This is the mass of the car after some of the original total mass had been removed. Subtract this mass from m = 1090kg
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: F=MA + Average Acceleration etc.
  1. Average speed, etc. (Replies: 9)

  2. Average Acceleration (Replies: 2)

  3. Average acceleration (Replies: 1)

  4. Average acceleration. (Replies: 12)

  5. Average acceleration (Replies: 4)

Loading...