3 - (a) What is the period of rotation of Earth in seconds? (b) What is the angular velocity of Earth? (c) Given that Earth has a radius of 40,075 km at its equator, what is the linear velocity at Earth's surface?

a) The Earth makes 1 rotation in 24 hours. In seconds:

24 hr * (3600 s / hr) = 86400 s

b) 1 rotation is 2π radians. So the angular velocity is:

2π rad / 86400 s = 7.27*10⁻⁵ rad/s

c) The earth's linear velocity is the angular velocity times the radius:

40075 km * 7.27*10⁻⁵ rad/s = 2.91 km/s