Question

How long is the minute hand on a clock whose tip travels 15 cm from 1:15 to 1:30 to the nearest tenth?

Answer 1

The length of minute hand is 9.5 cm

Explanation:

We are given the minute hand move from 1:15 to 1:30

Time for 1:30 to 1:30 = 15 minutes

Tip of minute hand move 15 cm in 15 minutes.

In 60 minutes = 360°

In 1 minute = 6°

In 15 minutes = 90°

Formula:
`\theta=(L)/(r)`

`\theta=90^\circ`

Now we change
`\theta=90^\circ` into radian

`Radian=(\pi)/(180^\circ)* 90^\circ=(\pi)/(2)`

L=15 cm

R = Length of minute hand.

`(\pi)/(2)=(15)/(R)`

`R=(30)/(\pi)\approx 9.5`

Hence, The length of minute hand is 9.5 cm