a construction worker is carrying a load of 40 kilograms over his head and is walking at a constant velocity. if he travels a distance of 50 meters, how
much work is being done?

0 J

Explanation:

Work is force times distance in the direction of the force (the dot product of the force and distance vectors).

W = F · d

Another way to write it is force times distance times the cosine of the angle between the force and distance vectors:

W = Fd cos θ

The force the worker is applying is vertical (there's no horizontal force because he is moving at constant velocity).  The direction he moves in is horizontal.  The two vectors are perpendicular, so there is no force component in the direction of motion, so there is no work being done.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide