1. The problem statement, all variables and given/known data A thrust-beam space vehicle works by bearing a sort of sail which feels the push of a strong steady laser light beam directed at it from earth. If the sail is perfectly reflecting, calculate the mass of light required to accelerate a vehicle of rest mass M0 up to a fixed value of θ. 2. Relevant equations total energy is conserved, So E=mc^2-(1/2)(M0+m)v^2=0 so, dE/dt=0 because energy is conserved. 3. The attempt at a solution dE/dt=0-2/2(M0+m)vdv/t=0 so (M0+m)=0, or m=M0. it is known that the rest mass of photon has energy, but it's not known whether it will apply a force on the object it hits, from the equation, there is a change in momentum, but not in force. in fact, the change is momentum and acceleration is zero. where can I find solution manuals for Special relativity A.P. French The M.I.T introductory physics series?