Say you were at mission control on Earth. You use radio waves to say "Hello" to an
astronaut on Mars when Mars is 84,000,000
km from Earth. The astronaut hears your "Hello"
280 seconds after you spoke the word. How do
you explain this time lag?

Avalue that describes how heavy an object is and is related to the force of gravity is

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

Awater-filled u-tube manometer is used to measure the pressure inside a tank that contains air. the water level in the u-tube on the side that connects to the tank is 5 ft above the base of the tank. the water level in the other side of the u-tube (which is open to the atmosphere) is 2 ft above the base. determine the pressure within the tank.