There are mainly three ways to eject an electron from the surface of metals. What are those?

Explain one physical process for release of electron from surface of a metal.

What is the value of escape velocity from the surface of (/) earth, (//) moon?

What is escape velocity? Find an expression for the escape velocity of a body when projected from the surface of the earth. Show that the escape velocity form the earth's surface is about 11.2 km/sec.

As you have learnt in the text, a geostationary satellite orbits the earth at a height of nearly 36,000 km from the surface of the earth. What is the potential due to earth’s gravity at the site of this satellite? (Take the potential energy at infinity to be zero). Mass of the earth = 6.0 xx 10^24 kg, radius = 6400 km

The minimum energy required for the electron emission from the metal surface can be supplied to the free electrons by one of some physical processes. What are they.

An echo was heard after 3s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 ms^-1 ?

Three persons walk along a circle and require 10m, 15m and 18 m respectively to complete the circle. They start to walk along the circle from the same point and at the same time. Find after what time they meet again at the starting point for the first time.

The work function of a metal is 3.45 eV. Calculate what should be the maximum wave length of a photon that can eject photo - electron from the metal.