Question

the large hand of a clock is 42cm long how much distance does its extremity move is 20 minutes​

Answer 1

Angle rotated in 60 mm=360 o θ= angle rotated in 20 min⇒ 60360 ×20⇒120 o θ⇒( 32π )∴P=rθ=(42)× 32π ⇒28 π cm

Angle rotated in 60 mm=360 o θ= angle rotated in 20 min⇒ 60360 ×20⇒120 o θ⇒( 32π )∴P=rθ=(42)× 32π ⇒28 π cm∴ the extremity of the hand moves 28 pi cms.

Answer 2

Answer:

As we know that the large hand means minute hand.

In 60 minutes , minute hand complete 1 cycle means it covered 2πr distance.

Step-by-step explanation:

minutes distance covered

60. 2πr

20. (20/60) × 2πr

In 20 min it covered (2/3)πr distance.

extremity means end point of a minute hand.

so r = 42 cm

dist covered in 20 minutes = (2/3) × 2π× 42

= 56 × (22/7)

= 176cm