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3 years ago

What is a radio wave?

2 answers:

7 0

An electromagnetic wave of a frequency between about 104 and 1011 or 1012 Hz, as used for long-distance communication

likoan [24]3 years ago

4 0

Answer: Radio waves are invisible rays that only radio telescopes can detect.

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A rigid tank A of volume 0.6 m3 contains 5 kg air at 320K and the rigid tank B is 0.4 m3 with air at 600 kPa, 360 K. They are co

neonofarm [45]

Answer:

the internal energy of the mixture at final state = 238kJ/kg

Explanation:

Given

V= 0.6m³

m=5kg

R=0.287kJ/kg.K

T=320 K

from ideal gas equation

PV = nRT

where P is pressure, V is volume, n is number of mole, R is ideal gas constant , T is the temperature.

Recall, mole = mass/molar mass

attached is calculation of the question.

6 0

3 years ago

What must a mechanical wave travel through

konstantin123 [22]

A mechanical wave always consists of wiggles in some kind of material stuff. The material stuff may be air, water, rock, wood, steel ... almost anything, as long as it's some material. In general, whatever the waves are moving through is called the "medium". If there isn't any, like the vacuum in space, then mechanical waves can't travel there. For example, sound can't travel in space ... not even an inch.

5 0

3 years ago

The energy of a photon of light is ________ proportional to its frequency and ________ proportional to its wavelength.

nirvana33 [79]

The energy of a photon of light is directly proportional to its frequency and inversely proportional to its wavelength.

7 0

3 years ago

At time t=0 a grinding wheel has an angular velocity of 30.0 rad/s . It has a constant angular acceleration of 35.0 rad/s2 until

Rama09 [41]

Answer:

(A) 570 rad

(B) 10 s

Explanation:

The equations of motion for circular motions are used.

Initial angular velocity, $\omega_0 = 30.0 \text{ rad/s}$

Angular acceleration, $\alpha =35.0 \text{ rad/s}^2$

(A)

At t = 2.00 s, the angular displacement, θ, is given by

$\theta = \omega_0t+\frac{1}{2}\alpha t^2 = (30\times 2) + \frac{1}{2}\times35\times2^2=60+70 = 130\text{ rad}$

After this time, it decelerates through an angular displacement of 440 rad.

Total angular displacement = 130 + 440 rad = 570 rad

(B)

At the time the circuit breaker tips, the angular velocity is given by

$\omega = \omega_0+\alpha t = 30.0+(35.0\times 2) = 30.0+70.0 =100.0\ \text{rad/s}$

This becomes the initial angular velocity for the decelerating motion. Because it stops, the final angular velocity is 0 rad/s. The time for this part of the motion is calculated thus:

$\theta_2 = \left(\dfrac{\omega_i+\omega_f}{2}\right)t$