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Nutka1998 [239]
2 years ago
8

A train is moving past a crossing where cars are waiting for it to pass. While waiting, the driver of the lead car becomes sleep

y and rests his head on the steering wheel, unintentionally activating the car's horn. A passenger in the back of the train hears the horn's sound at a frequency of 433 Hz and a passenger in the front hears it at 411 Hz.
Find the train's speed and the horn's frequency, assuming the sound travels along the tracks. Take the speed of sound to be 343 m/s.
Physics
1 answer:
notsponge [240]2 years ago
3 0

Answer:

a) 8.94 m/s

b) 422 Hz

Explanation:

The horns frequency F(g) is given by

F(g) = (411 +433) / 2

F(g) = 844 / 2

F(g) = 422 Hz

The speed is the train is given by

F(r) = [V(s) + V(r)] / [V(s) + V(g)] * F(g)

Where,

F(r) = 433 Hz

F(g) = 422 Hz

V(s) = 343 m/s

V(g) = 0 m/s

V(r) = velocity of train

433 = [V(s) + V(r)] / [V(s) + V(g)] * F(g)

[343 + V(r)] / [343 + 0] * 422 = 433

[343 + V(r)] * 422 = 148519

343 + V(r) = 351.94

V(r) = 351.94 - 343

V(r) = 8.94 m/s

Therefore, the Velocity of receiver(train) is 8.94 m/s

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Answer:

α = 1930.2 rad/s²

Explanation:

The angular acceleration can be found by using the third equation of motion:

2\alpha \theta=\omega_f^2-\omega_i^2

where,

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θ = angular displacement = (1500 rev)(2π rad/1 rev) = 9424.78 rad

ωf = final angular speed = 0 rad/s

ωi = initial angular speed = (960 rev/s)(2π rad/1 rev) = 6031.87 rad/s

Therefore,

2\alpha(9424.78\ rad) = (0\ rad/s)^2-(6031.87\ rad/s)^2\\\\\alpha = -\frac{(6031.87\ rad/s)^2}{(2)(9424.78\ rad)}

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The elements least likely to form bonds are found in which group?<br> O 15<br> O 16<br> 017<br> O 18
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Explanation:
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A liquid is used to make a mercury-type barometer. The barometer is intended for space-faring astronauts. At the surface of the
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Answer:

Density of liquid = 4730 kg/m³

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Explanation:

Pressure, P = ρgh where ρ = density of liquid, g =9.8 m/s² and h = height of column at earth's surface = 2185 mm. Since P = atmospheric pressure, for mercury, P = ρ₁gh₁ where ρ₁ = 13.6 g/cm³ and h₁ = 760 mm

So, ρgh = ρ₁gh₁

ρ = ρ₁h₁/h = 13.6 g/cm³ × 760/2185 = 4.73 g/cm³ = 4730 kg/m³

The atmospheric pressure on planet X

P = ρg₁h₃     g₁ = g/4 and h₃ = 725 mm = 0.725 m

on planet X

P = ρg₁h₃ = (4730 kg/m³ × 9.8 m/s² × 0.725 m)/4 = 8401.7 N/m²

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The energy that is radiated to Earth by the Sun includes visible light, infrared radiation, ultraviolet radiation, and other typ
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Answer:

The energy that is radiated to Earth by the Sun includes visible light, infrared radiation, ultraviolet radiation, and other types. These different forms of radiation are distinguished based on what property? Sunlight is a mixture of electromagnetic waves, ranging from infrared to ultraviolet.

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(a) What is the current involved when a truck battery sets in motion 720 C of charge in 4.00 s while starting an engine? (b) How
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Answer:

(a) Current flowing through truck battery is 180 A

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Explanation:

(a) Given:

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The relation between current, charge and time is:

I = q/t

Substitute the suitable values in the above equation.

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(b) Given:

The charge on the calculator,q = 7.00 C

The current flowing through calculator, I = 0.3 mA = 0.3 x 10⁻³ A

Consider t be the time.

The relation between current, charge and time is:

t = q/I

Substitute the suitable values in the above equation.

t=\frac{1}{0.3\times10^{-3} }

I = 333.33 s

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