(15 points) 5. Out in free space (far from any other objects), a source of electromagnetic waves isotropically broadcasts a power of 45 kW. A square of deeply black material that is 24.0-cm on a side is located a fixed distance of 12.0 m away from the wave source. How long will it take for this material to absorb 3.5 J of energy?
If instead the material square in P5 is free to move, what will be its speed after it has moved 1.00 m? Let the mass of the square be 0.12 g.