kinematics questions from a new physics student


by Intr3pid
Tags: kinematics, physics, student
Intr3pid
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#1
Jan10-07, 12:52 AM
P: 39
Hi everyone

I have a few conceptual questions about velocity and acceleration.

Can an object increase in speed as its acceleration decreases? If it does, can you guys give me an example?

Can an object have zero velocity and nonzero acceleration at the same time?
Also give some examples please

Thanks
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gabee
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#2
Jan10-07, 01:08 AM
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P: 179
To the first question:

Yes. Imagine that while driving a car, you push all the way down on the accelerator. Your car begins to speed up, gaining velocity. Now you slowly let off the accelerator a bit. You are still speeding up (your velocity is increasing), but your acceleration has decreased (you aren't speeding up as fast as before).

To the second:

Yes, but only for a split second. The only time I can think of this happening is in the following situation. Imagine an object moving to the left. If you start to accelerate this object to the right, it will move slower and slower to the left until for just a moment it is perfectly still (velocity is zero), and then it starts moving to the right. So you have kept a nonzero acceleration and it had to pass through a certain point where it had zero velocity.
Hootenanny
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#3
Jan10-07, 03:51 AM
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Intr3pid, please do not post your questions in the tutorials section.


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