# Physics - Recall for Chapter 16: Circular Motion

> Source: https://ollybritton.com/notes/a-level/physics/recall-questions/chapter-16-circular-motion/ · Updated: 2022-04-20 · Tags: physics, a-level, school, recall-questions

## Flashcards
### 2022-04-20
##### What are the SI units of angular velocity??
$$
\text{rad s}^{-1}
$$

##### What is the word definition of angular velocity??
The rate of change of angle.

##### How can you calculate angular velocity $\omega$ from $T$ or $f$??
$$
\omega = \frac{2\pi}{T} = 2\pi f
$$

##### What is required for uniform circular motion??
A force that always acts perpendicular to velocity.

##### Why doesn't a centripetal force do any work on an object in circular motion??
The force is perpendicular to the motion.

##### How can you calculate the linear velocity $v$ from the time period $T$ for an object in circular motion??
$$
v = \frac{2\pi r}{T}
$$

##### How can you calculate linear velocity $v$ from angular velocity $\omega$??
$$
v = \omega r
$$

##### What is the direction of velocity of an object travelling in a circle at constant speed??
At the tangent to the circle it's moving along.

##### What provides the centripetal force for a car turning a corner??
Friction from the road on the tyres.

##### What provides the centripetal force on the moon??
The gravitational attraction of the Earth.

##### What is the name for the resultant force on an object in circular motion??
Centripetal force.

##### If a mass on a string is swung in a vertical circle, where is the tension the greatest??
At the bottom of the circle.

##### If a mass on a string is swung in a vertical circle, where is tension the least??
At the top of the circle.

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