Ceiling-mounted fluorescent lighting fixtures with total power equal to 400 W are used to produce an average illumination level of 600 lux on student desks in a particular classroom. If the classroom lights are on 10 hours a day for 200 days per year, calculate the annual energy used for lighting in this classroom.

A 800 kWh
B 2 kWh
C 2,000 Wh
D 2,000 kWh
E 800,000 kWh
F 600 kWh

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.