Einstein in `1905` proppunded the special theory of relativity and in `1915` proposed the general theory of relativity. The special theory deals with inertial frames of reference. The general theory of relativity deals with problems in which one frame of reference. He assumed that fixed frame is accelerated w.r.t. another frame of reference of reference cannot be located. Postulated of special theory of realtivity
● The laws of physics have the same form in all inertial systems.
● The velocity light in empty space is a unicersal constant the same for all observers.
● Einstein proved the following facts based on his theory of special relativity. Let v be the velocity of the speceship w.r.t a given frame of reference. The obserations are made by an observer in that reference frame.
● All clocks on the spaceship wil go slow by a factor `sqrt(1-v^(2)//c^(2))`
● All objects on the spaceship will have contracted in length by a factor `sqrt(1-v^(2)//c^(2))`
● The mass of the spaceship increases by a factor `sqrt(1-v^(2)//c^(2))`
● Mass and energy are interconvertable `E = mc^(2)`
The speed of a meterial object can never exceed the velocity of light.
● If two objects A and B are moving with velocity u and v w.r.t each other along the `x`-axis, the relative velocity of A w.r.t. `B = (u-v)/(1-uv//v^(2))`
The momentum of an electron moving with a speed `0.6 c` (Rest mass of electron is `9.1 xx 10^(-31 kg`)

Options

A. `1.6 xx 10^(-22) kgms^(-1)`
B. `2 xx 10^(-22) kgms^(-1)`
C. `5.46 xx 10^(-31) kgms^(-1)`
D. `5.46 xx 10^(-22) kgms^(-1)`

Answer

B

Explanation

`p = mv = ((9.1xx10^(-31))(3/5xx3xx10^(8)))/(sqrt(1-(3/5)^(2))) = 2 xx 10^(-22)kg ms^(-1)`