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Homework Help: A problem invovling Force, Impulse, Velocity and Acceleration

  1. Mar 7, 2007 #1
    1. The problem statement, all variables and given/known data
    Heres the problem i have been given in Grade 11 Physics for homework (keep in mind that i havent done calculus yet so dont do anything too tricky):

    A satellite of mass 240 kg moving in free space at a velocity of 6000m/s is struck by an unknown object which causes it to be deflected onto a new path at right angles to its original direction of motion in 0.5 s. Find the impulse which acted upon the satellite if it continued to move at the same speed after deflection. Diagramativally show the change in direction that would occur.

    2. Relevant equations

    I'm pretty sure that the equation Impulse=Force * time or F*t = mass * Acceleration will be in it.
    From the word problem i know that:
    M= 240kg T= 0.5s and velocity is 6000 m/s

    3. The attempt at a solution

    I think i need to find the acceleration so that i can find the force and then the impulse but im not sure how to go about that since the speed is the same after the direction as it is at the start
    I know that I = F * 0.5 but im really not sure how to find the Force
    I think that ill be able to do the diagram fine but for the rest a hefty shove in the right direction would be nice. Thanks in advance.
    Last edited: Mar 7, 2007
  2. jcsd
  3. Mar 7, 2007 #2
    Well... Impulse is Force *time. But it is also the change in momentum of the object.

    So the impulse required to stop the object is equal to its mass time its velocity.

    This requires a force acting over a certain period of time.

    Breaking the question into 2 parts we can imagine that there are two forces acting, one to stop the object and the other to pushe it off at right angles.

    First of all there is the impulse required to stop it. This will be equal in this case to the impulse to get it going again at right angles.

    Is this helpful?
  4. Mar 7, 2007 #3

    Yeah, thanks a heap
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