Question

1. A neutron has a rest mass of 1.68 × 10−27kg. How much kinetic energy would it possess if it was travelling at 0.800c?

2. How much energy would be required to produce a kaon particle at rest with a rest mass of 8.79 × 10−28kg?

3. The Sun radiates energy away at a rate of 3.9 × 1026W. At what rate is the Sun losing mass due to this radiation?

4. How many 100.0W light bulbs could be powered for one year by the direct conversion of 1.0g of matter into energy?

Answer 1

Solution:

Neutron Has rest mass, m0 = 1.68*10^-27 kg

Therefore, Kinetic energy would required if it was travelling at 0.800 C is 1/2 m0(v)^2 = 1/2*(1.68*10^-27)*(0.800C) = 4.8384*10^-11 Jule.

2. Rest mass of Kaon particle is m0=8.79*10^-28 kg

Therefore, Energy would be required to produce a kaon particle is m0*C^2 = (8.79*10^-28)*(3*10^8)^2 = 7.911*10^-11 Jule.

3.With the given rate by which the Sun loses energy , we can solve for the mass that the Sun is losing every second using the equation given by ,

m = E/c^2 = (3.9*10^26) / (3*10^8)^2 = 4.3*10^9 kg . The sun is losing mass at the rate of 4.3*10^9 kg per second.

4. The Conversion of 1g mass of matter into energy is E = mC^2 = (10^-3 kg ) * (3*10^8)^2 = 9*10^13 Jule.

Power required in One Year is P = E /t = (9*10^13) / (3.16*10^7) = 2.848*10^6 Watt.

Therefore, NO of Bulb requires = n = (2.848*10^6) / 100 = 28480 [Answer]