SOLUTION: The radius of the earth is 6380km. a) How far does a point on the equator travel in 24hours? b) Find the speed of a point on the equator in m/s.

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Question 712662: The radius of the earth is 6380km.
a) How far does a point on the equator travel in 24hours?
b) Find the speed of a point on the equator in m/s.
Answer by Simnepi(216) (Show Source):
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a)
the circumference of a circle = 2 * pi * radius
since the earth spins once on its axis every 24 hours then a point on the equator will travel a full revolution in that time.
so the point will travel 2 * pi * 6380km
using a calculator
2 * pi * 6380 = 40086.7222598km
rounding this to the nearest metre (3 decimal places) gives
40086.722km
b)
now we know how far and we want the speed in metres per second, we have to change 24 hours into seconds
there are 24 *60 minutes in 24 hours = 1440 minutes
there are 1440 * 60 seconds in 1440 minutes = 86400 seconds
since the point travels 40086722 metres in 86400 seconds
speed = distance divided by time
giving
= 463.96681713 m/s
rounding this to 2 d.p.
the point travels at 463.97 m/s