A car starts moving in a circle with a radius of $200 \text{ m}$. It has a constant tangential acceleration of $1{\text{m}\over {\text{s}}^{2}}$.

a. What is the angular acceleration?

b. What is the angular velocity of the car $10 \text{ s}$ after it started to drive?

Attempt: a. If the velocity grows by $1 \frac{\text{m}}{\text{s}}$, then it grows by $\frac{1}{2\pi R} \frac{\text{rad}}{\text{s}}$ and I should just convert the radians to degrees?

As for b, I am not sure at all. I am not sure about a. either. I could really use any help or guidance.


closed as off-topic by John Rennie, Martin, Kyle Kanos, Qmechanic Apr 27 '15 at 15:06

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – John Rennie, Martin, Kyle Kanos, Qmechanic
If this question can be reworded to fit the rules in the help center, please edit the question.


The angular acceleration $\alpha$ is just $\alpha = a/r = 1/200\textrm{rad/s}^2$ where $a$ is the tangential acceleration and $r$ the radius of the circle. Here, we can see that $\alpha$ is constant, which allows us to use the constant acceleration equations in their angular form.

For (b) you can use the angular constant acceleration equations. You have $\alpha$, $t$, and the starting angular velocity $\omega_0=0$. Using $$\omega_f = \omega_0+\alpha t$$ gives $$\omega_f = 0 + {1\over200}\times10= 0.05\textrm{rad/s}$$ For a list of these equations (hopefully they are familiar already but if not...) see http://en.wikipedia.org/wiki/Equations_of_motion#Constant_circular_acceleration


Not the answer you're looking for? Browse other questions tagged or ask your own question.