Question #7c8db

1 Answer
Oct 4, 2017

Whether you use ac=v2r or ac=ω2r depends on the manner in which the velocity or acceleration is stated.
Details follow...

Explanation:

In this problem, the acceleration is stated in metres per second2. This determines the units and also the form of the relation you must use, namely:

ac=v2r f

Had the acceleration been stated in radians per second2, you would use the ac=ω2r form.

Both formulas would yield the same result, of course, because v increases as r increases, but ω does not.

In other words, when r doubles, v2 increases by 22 times, and v2r increases by two times.

When r doubles, ω does not change, so ω2r doubles.

Finally, in the last part of the question, if ω is doubled, then ω2r increases by 22.

Hope that clears it up.