If the radius of the Earth is 6.4 x 10\(^6\)m, the escape velocity of a satellite from the Earth is?
[g = 10 ms\(^-2\)]

The component of vector X along the direction of vector Y is zero when

The correct unit of energy density is?

I. Work done by load is always less than the work done by effort.
II. All machines are made of levers, pulleys, screws and gear wheels.
III. A fishing rod is a machine.
Iv. Effort is always larger than load.
which of statements above about machines are true?

The energy associated with the emitted photon when a mercury atom changes from one state to another is 3.3 ev. calculate the frequency of the photon.


[e = 1.6 x 10-19c; h = 6.6 x 10-34js]