Current electricity is caused by flowing negatively charged particles.
By definition, we have that the work done is given by:

Where,
F: force in the direction of displacement
d: displaced distance
Substituting values we have:

Then, the power is given by:

Where,
t: time
Substituting values we have:


Answer:
The work done on the box is 100 Nm, and the power is 20 Nm/s.
It will take 13
seconds for the golf ball to hit the ground. The correct answer between
all the choices given is the last choice or letter D. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.
Answer:
η = 2.57%
Explanation:
Given:
Output power of the steam power plant, P(out) = 200 MW
Consumption of coal, m = 700 tons/h = (700 × 10³)/3600 kg/s= 194.44 kg/s
Heating capacity of the coal, Cv = 40000 kJ/kg
now,
Input power, P(in) = mCv
or
P(in) = 194.44 kg/s × 40000 = 7777.77 MW
thus,
efficiency, η = P(out)/P(in) = (200 MW) / (7777.77 MW) = 0.02571
or
η = 2.57%
At Korona100 I don’t think it’s 10, becz I remember having this question on my test/ quiz but I got it incorrect so yeah.