One of the spacecraft propulsion may be "light sail" - SLR film gains momentum upon impact by the light. The initial speed of the ship is equal to v1 = 7,9 km / s (the first space), the final velocity is v2 = 11,2 km / s (the escape). How many photons (particles of light) should be reflected on the "light sails", if: 1) the light falls on the "sail" along the normal; 2) The weight of the ship with the "sail" m = 500 m; 3) photon mass MF = 0.5 * 10-35 kg?

Detailed solution shorthand terms, formulas, laws used in the decision, the withdrawal of the calculation formula and the response.