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3 years ago

Help with the two questions above? Correct answers?

Physics

1 answer:

LenKa [72]3 years ago

7 0

(6) first choice: the frequency appears higher and wavelength is shorter.

The car approaches a stationary observer and so the sound will appear to have shorter wavelength. This creates an effect of its siren to sound with higher frequency than it would do if both were stationary.

(7) The Doppler formula for frequency in the case of a stationary observer and source approaching it is as follows:

$f_O = \frac{v}{v-v_s}\cdot f= \frac{343\frac{m}{s}}{(343-25)\frac{m}{s}}\cdot 400Hz \approx 431Hz$

The wavelength is then

$\lambda = \frac{343\frac{m}{s}}{431Hz}\approx 0.80 m$

The third choice "0.80m; 431Hz" is correct

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A 0.110-kg cube of ice (frozen water) is floating in glycerine. The glycerine is in a tall cylinder that has an inside radius of

creativ13 [48]

Answer

Δ h = 0.06 m

Explanation:

Given,

mass of ice cube = 0.11 Kg

inside radius of cylinder = 3.70 cm

density of water = 1000 Kg/m³

density of glycerin = 1260 Kg/m³

ice cube is floating on glycerin surface,

net force on the cube is equal to zero.

Buoyant force by glycerin is equal to the weight of cube

B = W

$\rho_g V g = m g$

$\rho_g (\pi r^2 h_1)= m$

$h_1= \dfrac{m}{\rho_g\pi r^2}$

$h_1= \dfrac{0.11}{1260\pi\times 0.037^2}$

h₁ = 0.0203 m

when ice melts it is completely turned into water

Volume of mass m of water

$V = \dfrac{m}{\rho_w}$

$\pi r^2 h_2 = \dfrac{m}{\rho_w}$

$h_2 = \dfrac{m}{\rho_w\pi r^2}$

$h_2 = \dfrac{0.11}{1000\pi\times 0.037^2}$

h₂ = 0.0803 m

distance by which height of liquid change

Δ h = h₂ - h₁

Δ h = 0.0803 - 0.0203

Δ h = 0.06 m

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3 years ago

A resistor and an inductor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is ma

tatuchka [14]

At the moment contact is made with the battery, the voltage across the inductor is zero

At the instant the switch is closed, there is no current in the resistor (the inductor has prevented that), and therefore, there is no voltage across the resistor

<h3>What is Voltage ?</h3>

When charged electrons (current) are forced through a conducting loop by the pressure of an electrical circuit's power source, they can perform tasks like lighting a lamp. In a nutshell, voltage equals pressure and is expressed in volts (V).

DC voltage and AC voltage are the two different types of voltage. In a battery, for example, the DC voltage (direct current voltage) is always of the same polarity (positive or negative). Positive and negative waves interchange within the AC voltage (alternating current voltage).

Learn more about Voltage here:

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2 years ago

PHYSICS QUESTION<br> please answer!! i’ll choose the brainliest

Licemer1 [7]

Explanation:

answer is in the photo attached

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3 years ago

What is the definition of Heat Transfer

Evgen [1.6K]

Answer:

Heat transfer is an engineering discipline that concerns the generation, use, conversion, and exchange of heat (thermal energy) between physical systems.

Explanation:

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3 years ago

Read 2 more answers

a circuit shown below is Wheastone Bridge used to determine the valve of unknown resistor X by comparison with three resistors M

stiv31 [10]

Answer:

X = 0.6

Explanation:

The resistance of the unknown resistor can be found by using the formula of the Wheatstone bridge:

$\frac{M}{N}=\frac{P}{X}\\\\\frac{850}{15} = \frac{33.48}{X}\\\\X = \frac{(33.48)(15)}{850}$