Work done on the crate is 1411.2 J
Explanation:
Work done is defined as the product of force and the distance moved by the object. The unit of work done is in joules and denoted by the symbol J.
Work done = F * d
where F represents the force and d represents the distance moved by the object.
mass = 72 kg , distance moved by the object is given by 2.0 m
Force F = mass * gravity = 72 * 9.8
= 705.6 N =706 N.
Work done = 706 * 2.0 = 1412 J.
ANSWER
0s to 3s
EXPLANATION
To find the time interval where the object was traveling more quickly, we have to find the velocity of the object during each interval.
From a position-time graph, we can obtain the velocity of the object from the slope of the graph in each interval. To find those slopes, we just have to divide the vertical difference by the time interval.
The interval from 0s to 3s:

The interval from 3s to 5s and the interval from 7s to 8s have a horizontal line, so the slope is zero and therefore the velocity is zero - meaning that the object was not moving during these periods.
The interval from 5s to 7s,

And the interval from 8s to 12s,

Two of these three velocities are negative. Negative velocity indicates that the object is moving backward.
From these velocities, the greatest one, in absolute value, is the one between 0s to 3s. During this interval, the object is moving backward but at the greatest velocity.
The answer is metabolic heat.
<span>Organisms from the higher trophic levels consume organisms from the lower trophic level and during that process, energy is lost as metabolic heat. Primary producers (plants) contain the greatest amount of energy originally from the sunlight. The next trophic level belongs to primary consumers that consume primary producers. During consumption, energy is lost. Similarly, secondary consumers eat primary consumers and energy is lost again. The highest trophic level is tertiary consumers that contains the least amount of energy.</span>