What is the average linear speed of Mercury about the Sun? (The distance from the Sun to Mercury is 5.80 1010 meters. The orbital period around the Sun is 88 days.)

Answer 1

Speed = circumference / time

Circumference = 2πr
= 2*π*5.8*10^10 m
= 1.16π*10^11 m

Time
= 88days * 24h/day * 60min/h * 60sec/min
=7603200 s

Speed
= distance /time
= 1.16π*10^11 / 7603200
= 47930 m/s
= 47.93 km/s