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2 years ago

Which two statements are true of electromagnetic waves?

Physics

1 answer:

Usimov [2.4K]2 years ago

3 0

Answer:

B and C

Explanation:

Because EMWs are varying magnetic and electric radiation traveling at 90° to each other propagating energy form one place to another through vibration of these magnetic and electric fields

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Find the acceleration of the system and the tension in the ropes for the system shown. The table mass is 30 kg and the hanging m

marusya05 [52]

The system's tension is 616 N and acceleration is 5.6 $m / s^{2}$

<u>Explanation:</u>

From newton’s second law of motion which state that net force acting on a body is product of mass of a body and acceleration of a body which is given as,

$F_{n e t}=m_{t o t} \times a$

Where,

$F_{n e t}$ is net force acting on body

$m_{\mathrm{tot}}$ is mass of body

a is acceleration of body

Given values

Table mass (m) = 30 kg

Hanging mass (m) = 40 kg

$a=\frac{F_{n e t}}{m_{\mathrm{tot}}}=\frac{m \times g}{m_{\mathrm{tot}}}$

Put the value for m = hanging mass = 40 kg and $g=9.8 \mathrm{m} / \mathrm{s}^{2}$ , we get

$a=\frac{40 \times 9.8}{30+40}=\frac{392}{70}=5.6 \mathrm{m} / \mathrm{s}^{2}$

The tension in the ropes, $T=(m \times g)+(m \times a)$

Here, m as hanging mass

T = tension, N or $k g m / s^{2}$

m = mass, kg

g = gravitational force, $9.8 \mathrm{m} / \mathrm{s}^{2}$

a = acceleration, $m / s^{2}$

$T = (40 \times 9.8)+(40 \times 5.6) = 392+224 = 616 N$

3 0

2 years ago

The length of a wooden rod is 25.5 cm. What is this length in:<br>(a) millimetres?<br>(b) metres?

larisa86 [58]

Answer:

$(a)255mm \\ (b)0.255m$

Explanation:

$(a)1cm = 10mm \\ 25.5cm = x$

Cross multiply

$1x = 25.5 \times 10 \\ x = 255mm$

$(b)100cm = 1m \\ 25.5cm = x$

cross multiply

$100x = 25.5 \\ \frac{100x}{100} = \frac{25.5}{100} \\ x = 0.255m$

hope this helps

brainliest appreciated

good luck! have a nice day!

4 0

3 years ago

Read 2 more answers

A wire of Nichrome (a nickel-chromium-iron alloy commonly used in heating elements) is 1.3 m long and 1.6 mm2 in cross-sectional

fredd [130]

Answer: 1.3 *10^6 Ω*m

Explanation: In order to explain this problem we have to use the following expression for the resistence:

R=L/(σ*A) where L and A are the length and teh area for the wire, respectively. σ is the conductivity of teh Nichrome.

Then, from mteh OHM law we have V=R*I so R=V/I=2/3.2=0.625 Ω

Finally we have:

σ=L/(R*A)=1.3/(0.625*1.6*10^-6)=1.3*10^6 Ω*m

5 0

2 years ago

An astronomy student, for her PhD, really needs to estimate the age of a cluster of stars. Which of the following would be part

LiRa [457]

Answer:

A. plot an H-R diagram for the stars in the cluster.

Explanation:

A star cluster can be defined as a constellation of stars, due to gravitational force, which has the same origin.

The astronomy student would have to plot an H-R diagram for the stars in the cluster and determine the age of the cluster by observing the turn-off point. The turn-off is majorly as a result of gradual depletion of the source of energy of the star. Thus, it projects off the constellation.

4 0

2 years ago

Analysis: (use a separate sheet of paper)

Zolol [24]

Speed, frequency and wavelength are interconnected to each other.

<h3>What happens to the wavelength if the frequency increases?</h3>

As a wavelength increases in size, its frequency and energy (E) decrease. As the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer.

The wave speed is equal to the product of its frequency and wavelength, which shows the relationship between frequency and wavelength.

So we can conclude that speed, frequency and wavelength are interconnected to each other.

Learn more about frequency here: brainly.com/question/254161

5 0

2 years ago