Problem 1. The mean life of a meson is 2 x 10- 6 s. Calculate the mean life of a meson moving with a velocity 0.9c?
Problem 2. Calculate the rest energy of electron and proton in eV. Given m = 9.11 x 10-31 kg e. and m P = 1.673 x 1()-21 kg.
Hint: E = m c2
Problem 3. At what speed will be mass of a body is 2.25 times its rest mass?
Problem 4. The binding energy of hydrogen is 13.6 eV. Find the loss of mass in the formation of one atom of hydrogen.
Hint: E =M C2
Problem 5. The rest mass of an electron is 9.1 x w-·31 kg. What will be its mass if it was moving with 4/51/z the speed of light?
Problem 6. A rocket is chasing enemy’s space-ship. An observer on the earth observes the speed of rocket to be 2.5 x 108m/sec and that of space-ship 2 x l0 8 m/sec. Calculate (i) the velocity of enemy’s ship as seen by rocket (ii) the velocity of rocket as seen by enemy.
Problem 7. The rest mass of an electron is 9.1 x 10-31 kg. What will be its mass if it was moving with 3/511′ the speed of light.
Hint: M= 9.1 x 10-31 / √ 1-(0.6)2 =11.38 x 10 -31 kg