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Answer:
5,886 Joules or 5.886 KJ.
Explanation:
FORMULA IN FINDING WORK is
W = F x D
Where W is working;
F is force; and
D is distance
However, let us first discuss what work is.
When there is an object being moved by a force through a certain distance, the measure of energy transfer is what we call WORK.
One of the most common units used in work is JOULES (commonly used as a unit of energy). It is the work by which 1 Newton (1N = 1 kg.m/sec²) of force is used/expended through a distance of 1 meter (1m).
Refer to the problem.
It is said that the 30 kg set of bricks is to be raised to a height of 20 meters. As we see, there is no force given. But recall that force (F) is the product of the mass (m) of an object and its acceleration (a)
F = ma
However, in the formula, (g = 9.81 m/s²) or acceleration due to gravity is used in replacement of (a) because the object is moving upward.
So now we have
F = mg
Thus, we have the new work formula as
W = (mg)(D)
Substituting the given values, we have
W = (mg)(D)
W = (30kg)(9.81 m/s²)(20m)
W = 5,886 kg.m²/sec² or W = 5,886 Joules
The work done in lifting the bricks is 5,886 Joules or 5.886 KJ.
~hope this helps~