A small 32-kilogram canoe broke free of its dock and is now floating downriver at a speed of 2.5 m/s. What is
1 answer:
You might be interested in
Answer:
The generator produces electrical energy at a rate of 1378125000 J per second.
Explanation:
volume of water falling each second is 1250
height through which it falls, h is 150 m
mass of 1 of water is 1000 kg
⇒mass of 1250 of water, m = 1250×1000 = 1250000 kg
acceleration due to gravity, g = 9.8
in falling through 150 m in each second, by Work-Energy Theorem:
Kinetic Energy(KE) gained by it = Potential Energy(PE) lost by it
⇒KE = mgh
= 1250000×9.8×150 J
= 1837500000 J
Electrical Energy = (KE)
= ×1837500000
= <u>1378125000 J per second</u>
Answer:
a) f' = 432 Hz
b) I = 8.12*10^-4 W/m^2
Explanation:
a) To calculate the frequency of sound waves that car receives, you take into account the Doppler effect. In this case (observer moves away of the source) you have the following formula:
(1)
where
f: frequency of the source = ?
v: speed of sound = 343 m/s
vo: speed of the observer = 40.0 m/s
vs: speed of the source = 0 m/s (stationary)
You replace the values of all parameters in the equation (1):
To calculate f' you first calculate the frequency of the sound wave, by using the following formula:
v: speed of sound
λ: wavelength = 0.700 m
Next, you replace the values of all parameters in the equation (1):
hence, the frequency perceived by the car is 432 Hz
b) To calculate the power of the sound wave, when the car is 70.0 maway from the speaker, you use the following formula:
P: power of the source = 50.0 W
r: distance to the source = 70.0 m
hence, the intensity is 8.12*10^⁻4 W/m^2