Astronomy | Astrophysics Answers

An airplane flies due south at 175km/h relative to the air. There is a wind blowing at 85 km/h to the east relative to the ground. What are the plane's speed and direction relative to the ground.

we know that photons have their rest mass zero then why does they bend due to gravity of earth?

If photons have zero mass, why are they subject to the gravitational force?

Why are satellite TV dishes in the Northern Hemisphere pointed South and in the Southern Hemisphere pointed North?

A source of light P placed at a distance x in front of a plane mirror of width D hangs vertically on a wall. A man walks in front of the mirror at a distance 2x from it. What is the greatest distance over which he can see the image of P in the mirror?

Calculate the escape velocity from a red giant's atmosphere. Assume that the stars mass is 1 M and its radius is 100 R. How does this compare with the speed at which a planetary nebula shell is ejected?
I already calculate the escape velocity and got 1.34 x 10^-12 I dont know how to go about the second portion of this question.

Thanks for taking the time to help me!

The apparent magnitude of star at distance of 100 parsec is 7. what is its absolute magnitude?

the period of rotation of mercury is 59 earth days. how many earth hours will this be?

what is the weight of a 236 kg object on the surface of venus if the radius of venus is 6,000 km and the mass of venus is a 4.87x10^24 kg?

two 1000kg asteroids are located 10m apart in the asteroid belt. waht is the gravitional attraction between them. B) if the mass of the first astroid triples, how would the force change?. C) if the mass of the first asteroid triples and then distance reduced by half, what would the new force be?