uniform circular motion problem (1 Viewer)

[clicker]

Through how many radians does a point on the surface of the earth move in 6 hours?
What is the speed of a point on the earth's equater? (radius of the earth is 6370km.)

 

[KFunk]

6 hours is a quarter of a day. We go through 2π radians in one day (full revolution) so in six hours we travel through π/2 rad.

Velocity = 2πr/T (where T is the period of 24 hours)

so our orbital velocity = 2xπx6370000/24x60x60

= 463.2 ms^-1 I hope it's right (I gotta head off) and I hope it helps .