Aforklift lifts 5 boxes from the ground to a height of 2 meters (m). the boxes push down with a force of 1000 newtons (n). how much work was done by the forklift to lift the boxes?

The boxes push downward with a force of 1000 N: this means the total weight of the boxes is 1000 N, and then the forklift must do an equal (and opposite) force in order to lift them.
The 5 boxes are lifted by an altitude of , so the work done by the forklift is equal to the product between the magnitude of the force done by the forklift times the distance covered by the boxes:

therefore, the efficiency is:

The reflection of the candle in the concave mirror formed an upside-down virtual image that is smaller than the candle.in other words. the answer is the third option, c