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प्रश्न
What is the kinetic energy of an electron in electron volts with mass equal to double its rest mass?
उत्तर
If m0 is the rest mass of an electron and c is the speed of light, then kinetic energy (E) of the electron = mc2 − m0c2. ...........(1)
According to the question,
m = 2m0
E = (2m0 − m0)c2
E= m0c2 = 9.1 × 10−31 × 9 × 1016 J
\[E = \frac{9 . 1 \times 9}{1 . 6} \times \frac{{10}^{- 15}}{{10}^{- 19}} = 51 . 18 \times {10}^4 eV = 511\text{ keV}\]
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संबंधित प्रश्न
Mark the correct statements:-
(a) Equations of special relativity are not applicable for small speeds.
(b) Equations of special relativity are applicable for all speeds.
(c) Nonrelativistic equations give exact result for small speeds.
(d) Nonrelativistic equations never give exact result.
If the speed of a rod moving at a relativistic speed parallel to its length is doubled,
(a) the length will become half of the original value
(b) the mass will become double of the original value
(c) the length will decrease
(d) the mass will increase
A rod of rest length L moves at a relativistic speed. Let L' = L/γ. Its length
(a) must be equal to L'
(b) may be equal to L
(c) may be more than L' but less than L
(d) may be more than L
When a rod moves at a relativistic speed v, its mass ________________ .
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(a) Calculate the rate which the sun is losing its mass.
(b) How long will the sun last assuming a constant decay at this rate? The present mass of the sun is 2 × 1030 kg.
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Choose the correct answer from given options
The graph showing the correct variation of linear momentum (p) of a charge particle with its de-Broglie wavelength (λ) is _____________.
