Answer:
W = 1250 J = 1.25 KJ
Explanation:
The work done by the boy is due to the change in the position of the cement vertically. Hence, the work done in this case will be equal to the potential energy of the cement:

where,
W = Work done = ?
mg = W = weight of cement = 500 N
h = height covered = 2.5 m
Therefore,

<u>W = 1250 J = 1.25 KJ</u>
It's most likely the combination of a bucket and the wheel.
Speed is the rate of distance traveled per unit of time without regards to direction.
<u>Explanation</u>:
Speed is the pace of separation traveled per unit of time, regardless of direction.
Speed is straightforwardly relative to separate when time is consistent and conversely corresponding to a time when separation is steady. Multiplying one's speed would mean multiplying one's separation went in a given measure of time. Multiplying one's speed would likewise mean splitting the time required to travel a given separation.