Rotational motion

Question 1

Define the centripetal force

Answer 1

the resultant force that acts towards the centre to cause circular motion

Question 2

How do you know there is a resultant force during circular motion?

Answer 2

direction changes
therefore velocity changes
therefore it is accelerating
therefore there is a resultant force

Question 3

How can you ensure you measure time period accurately?

Answer 3

1. measure 10T and then divide (reduce percentage uncertainty)
2. use a fiducial marker (accurate start and stop)
3. measure 3 x 10T (spot anomalies)

Question 4

Define angular speed

Answer 4

the rate of change of angular displacement

Question 5

When a car is cornering on horizontal road, what is providing the centripetal force?

Answer 5

friction