Question

The length of minute hand of clock is 14 cm. Calculate the speed at which the tip of minute hand moves

Answer 1

r = 14cm

Tip of minute clock travels distance = circumference of circle of radius 14cm in 60 minutes (= 3600 seconds)

Speed = Distance / Time
Speed = 2π*(14) / (3600)
Speed = 0.024 cm/s

Answer 2

The speed of movement of the tip of the minute hand is 0.244 m/s.

Solution:

We have the length of minute hand =14cm=r

Convert 14cm into m

That is 1m=100cm

14cm=0.14m

We have to find the speed of the tip in which the minute hand moves

We know that

Speed $=\frac{\text { Distance }}{\text { Time }}$

Distance$=2 \pi r$

Time=1 hour

1 hour has 60 minutes, each minute comprises of 60 seconds.

So, I hour = 3600 seconds.  

Hence by substituting the values we get

$=\frac{2 \pi r}{1 \text { hour }}$

$=\frac{2 \times 3.141 \times 0.14 m}{60 \times 60 s}$

$=0.244 \times 10^{-3} \mathrm{m} / \mathrm{s}$

= 0.0244 cm/s

Hence speed =0.0244 cm/s

Speed of the minute hand is 0.244 cm/s .