Circular Motion

Question 1

What is a radian?

Answer 1

A radian is the angle subtended at the centre of a circle by an arc equal in length to the radius.

Question 2

How do you go from degrees to radians?

Answer 2

Multiply the angle by pi/180

Question 3

How do you go from radians to degrees?

Answer 3

Multiply by 180/pi

Question 4

What is the definition of angular velocity?

Answer 4

The angular velocity of an object moving in a circular path is defined as the rate of change of an angle.

rad s*-1

Question 5

What is the definition of a centripetal force?

Answer 5

A force, which acts perpendicular to the direction of motion, that keeps a body moving with a constant speed in a circular path.
Always perpendicular.

Question 6

What is the definition of centripetal acceleration?

Answer 6

The acceleration of any object travelling in a circular path at constant speed, which always acts towards the centre of a circle.

Question 7

What is the condition for centripetal acceleration?

Answer 7

Provided that a force always remains at 90 degrees to the direction the object is moving in, a centripetal acceleration will be caused.

Question 8

How do you work out linear velocity?

Answer 8

At any point on a circular path, the linear velocity is always at a tangent to the circular path.

Question 9

What centripetal force causes a satellite in orbit of the earth, an electron going around a nucleus and a cyclist going round a bend?

Answer 9

Gravity
Electrostatic
Friction