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2 years ago

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Water is pumped from a lower reservoir to a higher reservoir by a pump that provides 20 kW of shaft power. The free surface of t

he upper reservoir is 45 m higher than that of the lower reservoir. If the flow rate of water is measured to be 0.03 m3/s, determine mechanical power that is converted to thermal energy during this process due to frictional effects.

1 answer:

kifflom [539]2 years ago

7 0

Answer:

6.5 kW

Explanation:

Input power = 20 kW = 20000 W

h = 45 m

Volume flow per second = 0.03 m^3 /s

mass flow per second = volume flow per second x density of water

= 0.03 x 1000 = 30 kg/s

Output power = m g h / t = 30 x 10 x 45 = 13500 W

Power converted in form of heat = Input power - Output power

= 20000 - 13500 = 6500 W = 6.5 kW

Thus, mechanical power converted into heat is 6.5 kW.

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There is change in frequency whenever source move relative to the observer.

From Doppler effect we can write as

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where

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$v_s=$ velocity of source

$v_0=$ velocity of observer

here $v_0=0$

$697=723\cdot (\frac{343-0}{343+v_s})$

$v_s=(\frac{f}{f'}-1)v$

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distance traveled by fork is given by

$v^2-u^2=2as$

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The mathematical representation of the two resistors connected in parallel is

$R_T = \frac{1}{R_1} +\frac{1}{R_2}$

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From the question $I_p =10I_s$

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Dividing equation 2 with equation 1

=> $\frac{10I_s}{I_s} =\frac{\frac{V_0 (R_1 +R_2)}{R_1 R_2}}{\frac{V_0}{R_1 +R_2}}$

$10 = \frac{(R_1+R_2)^2}{R_1 R_2}----(3)$

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Complete question is;

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(a) the work done by the force of gravity on the projectile,

(b) the change in kinetic energy of the projectile since it was fired, and

(c) the final kinetic energy of the projectile.

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Answer:

A) W = mgh

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W = F × h

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Thus; W = mgh

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Therefore, even if the angle is changed, workdone will not change because the equation doesn't depend on the angle.

B) Change in kinetic energy is simply;

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However, from conservation of energy, we now that change in kinetic energy = change in potential energy.

Thus;

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ΔKE = ΔPE

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