CH16

Question 1

What is angular velocity (w)

Answer 1

Defined as the rate of change of angle for an object moving in a circular motion 1.
It is measured in rads^-1, angle must be in radians and time in seconds.

Question 2

Define centripetal force

Answer 2

A force that keeps a body moving with a uniform speed along a circular path

Question 3

Why does centripetal force not effect the speed of an object

Answer 3

Centripetal force acts perpendicular to the velocity of that object. This force has no component in the direction of motion therefore no work is done on the object. As a result the speed remains constant.

Question 4

For objects with the same angular velocity, the linear velocity at any instant is ___ to the radius

Answer 4

Directly proportional

Question 5

What is centripetal acceleration and what is the formula

Answer 5

The acceleration of any object travelling in a circular path.
A= v^2/r

Question 6

How can circular motion be investigated ( set up)

Answer 6

Can be investigated by tying a bung, with mass m, to a piece of string and threading it through a glass tube. The other end of the string has weight with mass M suspended from it, providing centripetal force F = Mg, as the tension through the string is constant.

Question 7

How can circular motion be investigated (investigation)

Answer 7

The string is whirled in a circle and the time taken for a complete rotation is recorded.
The mass of the weight is altered and the experiment is repeated.
Equate mg = mv^2/r , resolve for r and show that the radius is the same.
Mass of bung - m