Astronomy | Astrophysics Answers

In what way does gravity change with distance from Earth?

What if someday the biggest black hole consumed absolutely everything into one singularity and it exploded. Would this basically "recycle" the entire universe?

An 85kg person is on the moon (moon acceleration due to gravity is 1.6ms) Contrast the mass and weight of this person on the moon

distant stars are luminous or non luminous source does they have their own light or not?

The brightest star in the sky is the star sirius. It is 2.64 pc distant, and has an apparent visual magnitude of mv= -1.4. If the pupil of the human eye has a diameter of 5mm, how many photons from sirius enter the eye per second?

why, the pluto is not one of the eight planets of solar system .

the asteroid has a mass 7.395x10^20 kg and a radius of 539.7km. what is g on the surface? the value of the universal gravitational constant is 6.67259x10^-11 N*m^2/kg^2
answer in units of m/s^2

12. An atom at rest emits light at 500nm. What is the observed wavelength if it is moving away from the observer at 10,000 km/sec?
3. What is the energy of a photon of  = 600 nm, and in what region of the spectrum does it lie?
2. What is the frequency of an electromagnetic wave of wavelength 0.2 m? In what part of the spectrum is the wave?

The rings of Saturn are composed of chunks of ice that orbit the planet. The inner radius of the rings is 73,000 km, while the outer radius is 170,000 km. Find the period of an orbiting chunk of ice at the inner radius and the period of a chunk at the outer radius. Compare your numbers with Saturn’s mean rotation period of 10 hours and 39 minutes. The mass of Saturn is 5.69 x 1026 kg.

The Earth and other planets go around the sun in what kind of orbits?