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Nata [24]
3 years ago
15

The heart has structures that are called_____. This allows the blood to move in one direction.

Physics
2 answers:
Anarel [89]3 years ago
5 0

Answer:

valves

The heart has four valves - one for each chamber of the heart. The valves keep blood moving through the heart in the right direction.

spayn [35]3 years ago
4 0

Answer:

Valves

Explanation:

The valves help the blood move in just one direction while the veins are many.

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The length of vector A is 93.8 meters and the length of Ay is 38.4 meters, then the length of A, must be
vaieri [72.5K]

Answer:

85.556metres

Explanation:

Using pythagorean theorem

C²=A²+B²

we have c as the hypotenuse vector A thus:

93.8²=A²+38.4²

93.8²-38.4²=A²

8794.44-1474.56=A²

7319.88=A²

A=85.556

3 0
3 years ago
Calculate the wavelength of each frequency of electromagnetic radiation: a. 100.2 MHz (typical frequency for FM radio broadcasti
Natalka [10]

Answer:

a). 100.2 MHz (typical frequency for FM radio broadcasting)

The wavelength of a frequency of 100.2 Mhz is 2.99m.

b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)

The wavelength of a frequency of 1070 khz is 280.3 m.

c. 835.6 MHz (common frequency used for cell phone communication)

The wavelength of a frequency of 835.6 Mhz is 0.35m.

Explanation:

The wavelength can be determined by the following equation:

c = \lambda \cdot \nu  (1)

Where c is the speed of light, \lambda is the wavelength and \nu is the frequency.  

Notice that since it is electromagnetic radiation, equation 1 can be used. Remember that light propagates in the form of an electromagnetic wave.

<em>a). 100.2 MHz (typical frequency for FM radio broadcasting)</em>

Then, \lambda can be isolated from equation 1:

\lambda = \frac{c}{\nu} (2)

since the value of c is 3x10^{8}m/s. It is necessary to express the frequency in units of hertz.

\nu = 100.2 MHz . \frac{1x10^{6}Hz}{1MHz} ⇒ 100200000Hz

But 1Hz = s^{-1}

\nu = 100200000s^{-1}

Finally, equation 2 can be used:

\lambda = \frac{3x10^{8}m/s}{100200000s^{-1}}

\lambda = 2.99 m

Hence, the wavelength of a frequency of 100.2 Mhz is 2.99m.

<em>b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)</em>

<em> </em>

\nu = 1070kHz . \frac{1000Hz}{1kHz} ⇒ 1070000Hz

But  1Hz = s^{-1}

\nu = 1070000s^{-1}

Finally, equation 2 can be used:

\lambda = \frac{3x10^{8}m/s}{1070000s^{-1}}

\lambda = 280.3 m

Hence, the wavelength of a frequency of 1070 khz is 280.3 m.

<em>c. 835.6 MHz (common frequency used for cell phone communication) </em>

\nu = 835.6MHz . \frac{1x10^{6}Hz}{1MHz} ⇒ 835600000Hz

But  1Hz = s^{-1}

\nu = 835600000s^{-1}

Finally, equation 2 can be used:

\lambda = \frac{3x10^{8}m/s}{835600000s^{-1}}

\lambda = 0.35 m

Hence, the wavelength of a frequency of 835.6 Mhz is 0.35m.

6 0
3 years ago
According to the law of conservation of energy, which statement must be
alina1380 [7]

Answer: THE ANSWER IS C!

The total energy of a system can decrease only if energy leaves the system.

Explanation: Apex!

7 0
3 years ago
Please help I need this fast
Ghella [55]
The solution has reacted.
5 0
3 years ago
The light from Star 1 reaches Star 3 in 138 years and Star 2 in 63 years. Which of these conclusions about the stars is correct?
krek1111 [17]

The correct answer is A


6 0
4 years ago
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