Question

The short and long hands of a clock are 4 cm and 6 cm respectively then find the sum of the distances travelled by their tips in 48 hours

Answer 1

distance travelled by short hand is equal to 2πr for 12 hrs
therfore for 48 hrs 4* 2πr
= 4*2*22/7*4
=704/7 cm (or)
= 100.57 cm
distance travelled by lond hand is equal to 2πr for 12 hrs
therefore for 48 hrs 4*2πr
= 4*2*22/7*6
= 1056/7 cm (or)
= 150.85 cm
sum of these two = 100.57+150.85
= 251.42 cm

Answer 2

Answer:

Given :

Length of short hand = 4 cm

Length of long hand = 6 cm

We know short hand make 1 revolution in 12 hours while long hand in 1 hour.

Distance travelled by short hand in 48 hours = 4 × 2 π × 4 = 32 π cm

Distance travelled by long hand in 48 hours = 48 × 2 π × 6 = 576 π cm

Total distance travelled = 32 π cm +  576 π cm = 608 π cm

Therefore ,  sum of distances travelled by their tips in two day is 608 π cm.