Q1. Every day our Earth receives 1.55×1022 J energy from the Sun. If we were able to use 0.85 percent of this energy to accelerate spaceships, then how various missions will be possible in one year?
Q2. If a 90 light bulb emits 5.0 of the input energy as visible light (average wavelength 550) uniformly in all directions, approximation how many photons per second of visible light will strike the pupil (4.0 diameters) of the eye of an observer 3.0 away?