In which of the following situations is the greatest amount of work accomplished?

a boy lifts a 2-newton box 0.6 meters.
a boy lifts a 4-newton box 0.6 meters.
a boy lifts a 6-newton box 0.3 meters.
a boy lifts a 9-newton box 0.3 meters.

work = force x distances

A - moving 2 newton's up 0.6 meter = 1.2 joules
B - moving 4 newton's up 0.6 meter = 2.4 joules
C - moving 6 newton's up 0.3 meter = 1.8 joules
D - moving 9 newton's up 0.3 meter = 2.7 joules
The greatest amount of work is in example D. 

 D is your answer.

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.

the answer is true. hope it .