The Work Done In Lifting A 30 Kg Set Of Bricks To A Height Of 20m Is
The work done in lifting a 30 kg set of bricks to a height of 20m is
We all know the FORMULA IN FINDING WORK is
W = F x D
Where W is work;
F is force; and
D is distance
However, let us first discuss what work really 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/sec^2) 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 are to be raised in a height of 20 meters. As we see, there is no force given. But recall that force (F) is the product of mass (m) of an object and its acceleration (a)
F = ma
However, in the formula, (g = 9.81 m/s^2) 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/s^2)(20m)
W = 5,886 kg.m^2/sec^2 or W = 5,886 Joules
Thus, the work done in lifting the bricks is 5,886 Joules or 5.886 KJ.
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