My teacher asked a question asking which of the following are always true, and one of the statements was:
A constant force is needed to keep the object moving at a constant velocity.
I know that maybe he said it's false because it should be acceleration instead of velocity, but I think that it may be true; at least up to what we have covered so far.
If something is moving in a circle it takes a constant force towards the center of the object to keep it at a constant velocity, and if something is moving in a straight line it takes a constant force of 0, to keep it's velocity constant.
Did I miss something or am I mistaken?
2007-10-12 12:56:22 · 2 answers · asked by greeneggs4spam 3 in Science & Mathematics ➔ Physics
The initial statement is false, barring the constant of 0, as you mention, but that is not what your teacher is getting at.
If something is moving in a circle it does NOT travel at the same velocity (it's direction of motion is constantly changing) even if the SPEED remains constant.
2007-10-12 13:08:38 · answer #1 · answered by supastremph 6 · 2⤊ 0⤋
notice that velocity and force are not scalars, but vectors. so when an object is moving in a circle, the velocity vector is changing
at last, a constant force of 0 is a paradox, because I can say it is changing the velocity vector by 0 ! so it doesn't exist...
2007-10-12 20:33:24 · answer #2 · answered by Anonymous · 0⤊ 1⤋