Question1
What is relative velocity (in meters per second) between an observer on earth and a galaxy where the H-beta line of Hydrogen is calculated to be 622 nm? (The wavelength of the H-beta line as considered at rest in the laboratory is 486 nm.)
Question2
How fast is typical oxygen molecule (with a mass of 5.31e-26 kg) traveling while it is at a temperature of 440 Kelvins?
Question3
Assume you wish to measure the mass of a planet. To do so, you place a test mass in orbit around planet at a distance of 6.6e+8 meters from the center of the planet. You discover that the orbital period is 2.1e+5 seconds. What is mass of the planet?