Astronomy | Astrophysics Answers

The mean free path of photons in stars is of the order of 0.2 cm. Show that the time taken for a photon to reach the surface of a star of radius 4 RQ is of the order of one million year.

The length of second pendulum is decreased by 0.3 cm when it is shifted to chennai from london. If the acceleration due to gravity at London is 981 cm/sec^2, the acceleration due to gravity at chennai is :

Two ping-pong balls, each with a positive charge of 2.5 x 10^-5 C, are located 9.0 cm apart. Determine the size of the electric force between them. Would this be enough force to support a 70 kg person against the downward force of gravity?

The mean free path of photons in stars is of the order of 0.2 cm. Show that the time
taken for a photon to reach the surface of a star of radius 4 Ro is of the order of one
million year.

Explain how sunspots survive for so long even though they are surrounded by hotter
matter. (A 5 marks answer is needed, so please don't give a brief answer)

significant digit for 1,345,000

What are the 3 types of Radioactivity?

What are the two types of Nuclear energy?

Which type powers stars?

Which type is used in nuclear power plants?

In what ways are sound and light waves similar? In what ways are sound and light waves different?

What causes electric fields?

What causes magnetic fields?