Question

You leave your love to find a new home for humanity by taking a rocket to explore the universe. The
rocket uses solar and nuclear fission energy sources. You are both 30 years old when you depart. You
return 80 years younger than your love at 41 years old. The nuclear fuel has 92 protons and 143
neutrons with a mass of 4.3857876E-25kg, which is hit by one neutron to cause a fission to occur. The
solar panel has a work function of 821.428571428571eV.

1 The tip of your rocket releases a spent nuclear fuel canister in the direction of motion at 0.75c.
What is the fuel canister's velocity as observed by your love in terms of the speed of light?
2. If a nuclear fuel cannister has a mass of 156kg when you are with your love, what will its mass
be the instant you are moving at 0.6c relative to your love?
3. If a photon of wavelength 0.756nm is incident on the solar panel, what will the kinetic energy of
the ejected electron be? [eV]
4. What would the wavelength of the ejected electron be if treated non-relativistically? [m]
5. In each fission reaction the sum of the masses of all the particles after the reaction is equal to
the sum of all the particles used to cause the reaction. What is the energy released in each
individual fission reaction? [J]

6. What will the number of neutrons in the nuclear fuel be after beta decay?

7. What will the number of protons in the nuclear fuel be after beta decay?
8. What will the number of neutrons in the nuclear fuel be after alpha decay?
9. What will the number of protons in the nuclear fuel be after alpha decay?

Answer 1