Karl measures the current through a resistor. What else will he need to measure in order to work out its resistance?
1 answer:
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Answer:
<em>The power required by the pump is nearly 230.588 kW</em>
Explanation:
Flow rate of the pump Q = 1 m^3/s
the head flow H = 20 m
specific weight of water γ = 9800 N/m^3
efficiency of the pump η = 85%
First note that specific gravity of water is the product of the density of water and acceleration due to gravity.
γ = ρg
where ρ is density. For water its value is 1000 kg/m^3
g is the acceleration due to gravity = 9.81 m/s^2
The power to lift this water at this rate will be gotten from the equation
P = ρgQH
but ρg = γ
therefore,
P = γQH
imputing values, we'll have
P = 9800 x 1 x 20 = 196000 W
But the centrifugal pump that will be used will only be able to lift this amount of water after the efficiency factor has been considered. The power of pump needed must be greater than this power.
we can say that
196000 W is 85% of the power of the pump power needed, therefore
196000 = 85% of
where is the power of the pump needed
85% = 0.85
196000 = 0.85
= 196000/0.85 = 230588.24 W
<em>Pump power = 230.588 kW</em>
Answer:
The answer is below
Explanation:
a) The change in energy is the difference between the final energy and the initial energy.
ΔE (energy change) = Ef (final energy) - Ei (initial energy)
The negative sign shows that energy is lost to the environment. Hence 0.334 J is lost to the environment.
b) According to the law of conservation of energy, energy cannot be created or destroyed but transformed from one form to another.
The oscillating object loses energy due to wind resistance, friction between the spring and the object. Given that the air is frictionless, hence the energy loss is due to friction which is converted to heat.