The emissivity of the earth is 0.5
The emissivity of the earth is calculated by the Stefan's law

I’m not sure what variables you are given, but since work = force x distance, and force = mass x acceleration, you could use work = mass x acceleration x distance
Answer:
house C is at a distance of 20 m from the reference point and house E is at a distance of 40 m from the reference point. therefore position of house C relative to house E = 40 - 20 = 20 meter.