Question

if the hour hand of a clock is 7cm long ,find the distance covered by the tip of the hour in 40 days

Answer 1

Area covered by hour hand in one hour = πr2
= 22/7 *7*7
154 cm2

Distance covered in 40 days = 154*24*40
= 147840 cm2

Answer 2

Radius=7cm
Distance travelled in 1 hour=Circumference of the circle made by the revolution of the hour hand=
circumference of circle=
$2 \times \pi \times r$
=
$2 \times 3.14 \times 7 = 43.96cm$
Distance travelled in 1 day=
$43.96 \times 24 = 1055.04cm$
Distance travelled in 40 days=
$1055.04 \times 40 = 42201.6cm$
and
$42201.6cm = 422.016m$