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3 years ago

Which statements below are true?

1 answer:

7 0

The correct statements are that the speed decreases as the distance decreases and speed increases as the distance increases for the same time.

Answer:

Option A and Option B.

Explanation:

Speed is defined as the ratio of distance covered to the time taken to cover that distance. So Speed = Distance/Time. In other words, we can also state that speed is directly proportional to the distance for a constant time. Thus, the speed will be decreasing as there is decrease in distance for the same time. As well as there will be increase in speed as the distance increases for the same time. So option A and option B are the true options. So if there is decrease in the distance due to direct proportionality the speed will also be decreasing. Similarly, if the distance increases, the speed will also be increasing.

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(TCO 4) A signal consists of only two sinusoids, one of 65 Hz and one of 95 Hz. This signal is sampled at a rate of 245 Hz. Find

storchak [24]

Answer:

65 Hz, 95 Hz, 150 Hz, 180 Hz, 310 Hz, 340 Hz

Explanation:

Given :

Frequencies of the sinusoids,

$f_{m_1}= 65 \ Hz$ , and

$f_{m_2}= 95 \ Hz$

Sampling rate $f_s = \ 245 \ Hz$

The positive frequencies at the output of the sampling system are :

$f_{o_1}=\pm f_{m_1} \pm nf_s, f_{o_2}=\pm f_{m_2} \pm nf_s$

When n = 0,

$f_{o_1}= f_{m_1} = 65 \ Hz,\ \ f_{o_2}= f_{m_2} = 95 \ Hz$

when n = 1,

$f_{o_1}=\pm f_{m_1} \pm f_s, \ \ f_{o_2}=\pm f_{m_2} \pm f_s$

$f_{o_1}= \pm 65 \pm 245,\ \ f_{o_2}=\pm 95 \pm 245$

$f_{o_1}= 180 \ Hz, 310 \ Hz,\ \ f_{o_2}= 150 \ Hz,340 \ Hz$

When n = 2,

$f_{o_1}= \pm 65 \pm 2(245),\ \ f_{o_2}=\pm 95 \pm 2(245)$

$f_{o_1}= 555 \ Hz, 425 \ Hz,\ \ f_{o_2}= 395 \ Hz,585 \ Hz$

Therefore, the first six positive frequencies present in the replicated spectrum are :

65 Hz, 95 Hz, 150 Hz, 180 Hz, 310 Hz, 340 Hz

8 0

3 years ago

Suppose that a spiral galaxy is located at the center of a spherically symmetric dark matter halo

Novosadov [1.4K]

To solve the problem it is necessary to use the concepts of Orbital Speed considering its density, and its angular displacement.

In general terms the Orbital speed is described as,

$V_{orbit} = \sqrt{\frac{G\rho 4\pi r^3}{3}}$

PART A) If the orbital speed of a star in this galaxy is constant at any radius, then,

$\frac{4\pi G\rho r}{3} = \frac{v^2}{r}$

$\frac{4\pi G\rho r}{1} = \frac{3v^2}{r}$

$\frac{\rho}{1} = \frac{3v^2}{r^2 4\pi G}$

$\rho = \frac{1}{r^2}$

PART B) This time we have $v=\omega t$ , where $\omega$ is the angular velocity (constant at this case)

$\frac{4\pi G\rho r}{3} = \frac{v^2}{r}$

$\frac{4\pi G\rho r}{3} = \frac{(\omega r)^2}{r}$

$\rho = \frac{3\omega r}{4\pi Gr}$

$\rho = \frac{3\omega^2}{4\pi G} \propto constant$

PART C) If the total mass interior to any radius r is a constant,

$\frac{4\pi G\rho r}{3} = \frac{v^2}{r}$

$\frac{GM}{r^2}=\frac{v^2}{r}$

$v = \sqrt{\frac{GM}{r}}$

$v= \sqrt{\frac{1}{r}}$

3 0

4 years ago

A barge of mass 5.00 ×104 kg is pulled along the Erie Canal by two mules, walking along towpaths parallel to the canal on either

boyakko [2]

Answer: 219,344.5 j

Explanation:

from the question we have the following parameters

mass of barge (m) = 5 x 10^4 kg

angle of ropes (θ) = 45 degrees

force by each mule (F1) = 1.10 kN = 1100 N

force by each mule (F2) = 1.10 kN = 1100 N

distance (s) = 141 m

work done by the mules = force x cos θ x distance

since we are calculating the force of both mules we have to both mules before we can use in the equation

force = 1100 + 1100 = 2200 N

work done = 2200 x cos (45) x 141

work done = 219,344.5 j

5 0

3 years ago

Candace is interested in learning more about colors. Which question about colors could be answered through scientific investigat

tatuchka [14]

I think the correct answer from the choices listed above is the first option. Candace is interested in learning more about colors. The question about the colors that <span>could be answered through scientific investigation would be:

</span>Which color bends the most to make a rainbow?

Hope this helps. Have a nice day.

7 0

3 years ago

Read 2 more answers

Momentum = ___________.

posledela

The answer must be a mass x velocity

4 0

3 years ago