Example: 17km = 17 times 10 to the third power = 1.7 times 10 to the fourth power=__________ =___________ um

Example: 17km = 17 times 10 to the third power = 1.7 times 10 to the fourth power=__________ =___________ um

=（6.7×10^-4 dm)=(6.7×10^-9 um)

The earth can be seen as a sphere with a radius of 6.4 times 10, and the latitude of Beijing is about 40 degrees
The earth can be seen as a cubic sphere with a radius of 6.4 times 10, and the latitude of Beijing is about 40 degrees. What is the angular velocity and linear velocity of the two objects at the equator and Beijing in uniform circular motion with the earth's rotation?

The angular velocity of circular motion is the same, w = 2 π / (24 × 3 600) rad / S = 7.3 × 10-4 rad / s
The linear velocity V1 = ω r = 4 653 M / s for objects on the equator and V2 = ω R1 = ω RCOs 40 ° 3.7 × 103 M / s for objects in Beijing

The earth is a sphere with a radius of 6.4 times 10 to the power of 3 km. The latitude of Beijing is 40. The two objects at the equator and Beijing move with the earth in a circular motion with angular velocity

(6.4 × 1000km × cos40) / (24 hours × 60min × 60s) = how many runs per second (line speed)
The angular velocity is the same all over the world, 15 degrees per hour (except the pole)