Answer:
Minimum work = 5060 J
Explanation:
Given:
Mass of the bucket (m) = 20.0 kg
Initial speed of the bucket (u) = 0 m/s
Final speed of the bucket (v) = 4.0 m/s
Displacement of the bucket (h) = 25.0 m
Let 'W' be the work done by the worker in lifting the bucket.
So, we know from work-energy theorem that, work done by a force is equal to the change in the mechanical energy of the system.
Change in mechanical energy is equal to the sum of change in potential energy and kinetic energy. Therefore,

Therefore, the work done by the worker in lifting the bucket is given as:

Now, plug in the values given and solve for 'W'. This gives,

Therefore, the minimum work that the worker did in lifting the bucket is 5060 J.
Which source of information is generally considered credible?
The best and most correct answer among the choices provided by the question is decreases <span>.
</span>The potential energy of the object <span>decreases.</span>
Hope my answer would be a great help for you.
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Answer:
a. E=1440KJ
b. E=360KJ
c. E=1.8 J
Explanation:
I have the power (Watts) is expressed as Energy (Joules) / Time (seconds), also I have to
so, for the lightbulb

Analogously, for the microwave

Now, I have to express the efficiency as Heat energy / power * 100 so
Done