Question

Example. An artificial satellite is moving in a circular orbit of radius 42250 km Calculate its speed if it takes 24 hours to revolve around the earth.

Solution. Radius of orbit = 42250 km Circumference of the orbit = 2πr
=2×22/7× 42250 km
Revolution time (t) = 24hour
= 24 x 60 x 60 s = 86400 s
circumference of orbit÷time=2πr÷t
Speed of satellite, v=circumference of orbit ÷time=2πr/t
=2× 22/7 X 42250 km /86400s = 3.07 km/s

please can you tell me why we put 60×60s here 24×60×60s=86400s
​

Answer 1

1 hour = 60 minutes

1 minute = 60 seconds

so 60 minutes = 60 × 60 seconds

24 hours = 24 × 60 minutes

= 24 × 60 × 60 seconds

Answer 2

Answer:

They have converted hours into second

1 hour = 60min

1 min=60sec

Therefore 1 hour =60x60sec=3600sec

Therefore 24 hours=3600x24=86400sec

Step-by-step explanation:

They have converted all values to their si unit