Here is a graph of speed vs time. If the object is moving to the east, which BEST describes the speed and velocity of the graph?

a ultrasonic wave at 8x10^4 Hz is emitted into a vien where the speed of sound in blood is 1570 m/s. the wave reflects off the r

Aneli [31]

Answer: 0.392 m/s

Explanation:

The Doppler shift equation is:

$f'=\frac{V+V_{o}}{V-V_{s}} f$

Where:

$f=8(10)^{4} Hz$ is the actual frequency of the sound wave

$f'=8.002(10)^{4} Hz$ is the "observed" frequency

$V=1570 m/s$ is the speed of sound

$V_{o}=0 m/s$ is the velocity of the observer, which is stationary

$V_{s}$ is the velocity of the source, which are the red blood cells

Isolating $V_{s}$ :

$V_{s}=\frac{V(f'-f)}{f'}$

$V_{s}=\frac{1570 m/s(8.002(10)^{4} Hz-8(10)^{4} Hz)}{8.002(10)^{4} Hz}$

Finally:

$V_{s}=0.392 m/s$

3 0

3 years ago

A frequency generator sends a 550 Hz sound wave through both water and ice.

Brums [2.3K]

Δλ = 3.103 m.

To solve this problem we have to know the speed of sound in both elements water and ice.

Element Speed of sound

Water (25°C) 1493 m/s

Ice 3200 m/s

The velocity of a wave is given by the equation v = λf, where λ is the wavelength, and f is the frecuency of the wave.

In order to calculate the wavelength we have to clear λ in the equation v = λf, resulting:

λ = v/f

Calculating the wavelength in both elements:

λ(water) = 1493 m/s / 550 Hz = 2.715 m

λ(ice) = 3200 m/s / 550 Hz = 5.818 m

So, the difference in wavelength between the wave produced in ice and the wave produced in water is:

Δλ = λ(water) - λ(ice) = 5.818 m - 2.715 m

Δλ = 3.103 m

3 0

4 years ago

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An AC adapter for a telephone-answering unit uses a transformer to reduce the line voltage of 120 V (rms) to a voltage of 9.0 V.

Illusion [34]

Answer:

1. The number of turns on the secondary output is 18

2. The root mean square power delivered to the transformer is 48 Watts.

Explanation:

A transformer is an electronic device that can be used for increasing or decreasing the value of a given voltage. It consists of primary coils and secondary coil of a definte number of turns. When voltage flows in the primary coil, it induces voltage in the secondary coil. The two types are: step-up and step down transformers.

1. For a given transformer,

$\frac{V_{s} }{V_{p} }$ = $\frac{N_{s} }{N_{p} }$

where $V_{s}$ is the value of the induced voltage in the secondary coil, $V_{p}$ is he voltage in the primary coil, and $N_{s}$ is the number of turns of the secondary coil, $N_{p}$ is the number of turns in the primary coil.