Question

If a worker pulls a \[10\] kg bucket up a \[25\] m well, how much work has he or she done?

Answer 1

Hint:To solve this question, we have to know that, if we pull any heavy object, vertically we have to extend some amount of force. this force which is mg is multiplied by the height or the displacement of the bucket gives the work done by the person who pulls the object. By the work energy theorem we know that the work is equal to the change in total energy of the object.

Complete step by step answer:
We are assuming here that W is the work done, when an object is raised to a height. Here, let us consider the mass of that object is m and the height is h. so, according to the formula, work done W is equal to mgh joules.
\[W = mgh\]
Here g is equal to acceleration due to gravity.
Now, we know that, the S.I. the unit of this acceleration is \[9.8m/{s^2}\].
Therefore, according to this question, the work done is, \[10 \times 9.8 \times 25 = 2450\] Joules.

Note: We can get confused between acceleration and acceleration due to gravity. We know that acceleration is the rate of change of velocity. When this velocity change happens due to gravity. The unit of this acceleration is meter per second. And we know that the rate of change of speed is equal to velocity. We can say g as the acceleration due to gravity and the value of g is \[9.8m/{s^2}\]. So, this is a very important knowledge we have to keep in our mind.