Question

The minute hand of a clock is 7m long. Calculate the distance covered and the displacement of minute hand of the clock from 9:00 am to 9:30 am.​

Answer 1

Answer:

3.33km

Explanation:

The clock has the minute hand with the length of 7 cm which moves from 9 am to 9 : 30 am, the distance covered and the displacement covered will be calculated as follows –

The displacement is the measure of the shortest distance between the two points of travel irrespective of the path followed.

Here, the minute hand initially is at 9 : 00

And finally at 9 : 30

So the shortest distance will the twice of the length of the minute hand as it fully stretches on either side of the clock.

Displacement = twice length of minute hand

\begin{gathered}\begin{array}{c}{\text {Displacement}=2 \times \text {length}} \\ {\text {Displacement}=2 \times 7}\end{array}\end{gathered}

Displacement=2×length

Displacement=2×7

Displacement = 14 cm

Distance is the measure of actual length covered in the total journey.

Here, distance is half of the circumference of the clock as travelled for 30 minutes.

Distance = circumference of half clock

Distance = circumference of half circle

\begin{gathered}\begin{aligned} \text {Distance} &=\pi \times \text { radius } \\ \text {Distance} &=\pi \times \text {length of minute hand} \end{aligned}\end{gathered}

Distance

Distance

=π× radius

=π×length of minute hand

Distance = 3.14 \times× 7

Distance = 21.98 m

Or Roughly Distance = 22