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Avg and instantaneous accel question 
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#1
Sep1703, 07:43 PM

P: n/a

hello again,
I am having trouble with this problem: A particle leaves the origin with an initial velocity v = (3.00i) m/s and a constant acceleration a = (1.00i  0.500j) m/s^2. When the particle reaches its max x coordinate, what are a)it's velocity and b) its position vector. Am I to assume that at the max the v = 0 m/s? That means I've got to assume that the motion is a parabola, but I don't think that I have enough information to assume that. Or do I? I would just like to know how to start this problem out. Can someone lead me in the right direction? Thanks! 


#2
Sep1703, 07:47 PM

P: 1,954

I think considering at max x, the x component of v (but not neccessarily the y!) to be zero is pretty reasonable, as you are looking for turning points.



#3
Sep1803, 05:13 AM

Math
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Thanks
PF Gold
P: 39,348

If v> 0 then the particle is still moving to the right: it's not yet at it's maximum x value.
If v< 0 then is already moving to the left: it's coming back from it's maximum x value. In either case, the particle is not AT it's maximum x value. In order to be AT it's maximum x value, the particle's speed MUST be 0 that's not an "assumption"! 


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