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stira [4]
3 years ago
13

Dolphins rely on echolocation to be able to survive in the ocean. In a 20 °C ocean, a dolphin produces an ultrasonic sound with

a frequency of 125 kHz. What is the wavelength of this sound, in meters?While remaining stationary, the dolphin emits a sound pulse and receives an echo after 0.220 s. How far away, in meters, is the reflecting object from the dolphin?
Physics
1 answer:
Firdavs [7]3 years ago
8 0

Answer:

wavelength =  0.01 m

distance = 162.8 m

Explanation:

Given that;

Speed of sound in water = 1,480 meters per second

Frequency of ultrasound = 125KHZ

From=

v=λf

v= speed of sound

λ= wavelength of sound

f= frequency of sound

λ= 1,480 ms-1/125 * 10^3 Hz

λ= 0.01 m

From

v = 2x/t

where;

v= velocity of sound in water

x= distance traveled

t = time taken

x = vt/2

x = 1,480 ms-1 *  0.220 s/2

x= 162.8 m

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Whitepunk [10]

The equation we can use here is:

v^2 = v0^2 + 2 a d

where v is final velocity, v0 is intial velocity, a is acceleration and d is distance

 

14^2 = 8^2 + 2 a (44)

<span>a = 1.5 m/s^2</span>

4 0
3 years ago
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Two cars are traveling in the same direction and with the same speed along a straight highway. Does either driver hear a differe
Trava [24]

Answer:

No, either driver can not hear a different frequency from the other car's horn than they would if the cars were stationary.

Explanation:

Either driver hear a different frequency from the other car's horn than they would if the cars were stationary if two cars are traveling in the same direction and with the same speed along a straight highway because neither driver experiences a Doppler shift

8 0
3 years ago
Light passes through glass window because of ____.
Amiraneli [1.4K]
Answer:
it’s transparent to all visible light

step-by-step explanation:
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4 0
3 years ago
A boy flies a kite with the string at a 30 degree angle to the horizontal. The tension in the string is 4.5N .
sp2606 [1]
How much work in J does the string do on the boy if the boy stands still? 

<span>answer: None. The equation for work is W = force x distance. Since the boy isn't moving, the distance is zero. Anything times zero is zero </span>
<span>--------------------------------------... </span>
<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite? </span>

<span>answer: might be a trick question since his direction away from the kite and his velocity weren't noted. Perhaps he just set the string down and walked away 11m from the kite. If he did this, it is the same as the first one...no work was done by the sting on the boy. </span>

<span>If he did walk backwards with no velocity indicated, and held the string and it stayed at 30 deg the answer would be: </span>
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<span>work = total force1 x 11 meters </span>
<span>--------------------------------------... </span>

<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite? </span>

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6 0
4 years ago
For what absolute value of the phase angle does a source deliver 71 % of the maximum possible power to an RLC circuit
kherson [118]

Answer: the absolute value of the phase angle is 28°

Explanation:

taking a look at expression for the instantaneous electric power in an AC circuit;

P = VI -------let this be equation 1

p is power, v is voltage and I is current;

for maximum power

P_max = V_rms × I_rms --------let this be equ 2

where P_max is the maximum power, V_rms is the rms value of voltage and I_rms is the rms value of current.

Also for average electric power in an AC circuit

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so p_max replaces V_rms × I_rms in equation 3

we now have

P_avg = P_max × cos²∅

so we substitute

expression for the given value of the average power is

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p_avg = P_max.78/100

for the expression of the average electricity in an AC circuit

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78/100 = cos²∅

to get the absolute value of phase angle

∅ = cos⁻¹ ( √(78/100))

∅ =  cos⁻¹ ( 0.8832)

∅ = 27.969 ≈ 28°

Therefore the absolute value of the phase angle is 28°

8 0
3 years ago
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