Explain what is meant by the term angular speed.

This diagram shows a rubber bung, of mass $200 \mathrm{g}$, on the end of a length of string being swung in a horizontal circle of radius $40 \mathrm{cm}$. The string makes an angle of $56°$with the vertical.

Calculate the tension in the string.

This diagram shows a rubber bung, of mass $200 \mathrm{g}$, on the end of a length of string being swung in a horizontal circle of radius $40 \mathrm{cm}$. The string makes an angle of $56°$with the vertical.

Calculate the angular speed of the bung

This diagram shows a rubber bung, of mass $200 \mathrm{g}$, on the end of a length of string being swung in a horizontal circle of radius $40 \mathrm{cm}$. The string makes an angle of $56°$with the vertical.

Calculate the time it takes to make one complete revolution

Explain what is meant by a centripetal acceleration.

A teacher swings a bucket of water, of total mass $5.4kg$, round in a vertical circle of diameter $1.8m$. Calculate the minimum speed that the bucket must be swung at so that the water remains in the bucket at the top of the circle.

A teacher swings a bucket of water, of total mass $5.4kg$, round in a vertical circle of diameter $1.8m$. Assuming that the speed remains constant, what will be the force on the teacher's hand when the bucket is at the bottom of the circle?

In training, military pilots are given various tests. One test puts them in a seat on the end of a large arm that is then spun round at a high speed, as shown.

Describe what the pilot will feel and relate this to the centripetal force.

In training, military pilots are given various tests. One test puts them in a seat on the end of a large arm that is then spun round at a high speed, as shown.

At top speed the pilot will experience a centripetal force equivalent to six times his own weight ($6mg$). Calculate the speed of the pilot in this test.