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Sunny_sXe [5.5K]
3 years ago
8

1. Astronomers measure the angle that the star appears to jump when viewing it from two different points in Earth's orbit. What

is this technique called?
A) Parsecs

B) Parallax

C) Luminosity

D) Mass transfer


3. What properties of a star are needed to calculate the stars's luminosity?


A) Size and apparent brightness

B) Mass and distance to the star

C) Temperature and diameter of the star

D) Apparent brightness and distance to the star


4. Which cool and bright stars are located in the upper right of the H-R diagram?


A) Red giant

B) Neutron stars

C) White dwarfs

D) Main sequence


5. What color are stars that are very hot and very bright?


A) Red

B) Blue

C) White

D) Yellow
Physics
2 answers:
bogdanovich [222]3 years ago
7 0

Answer:

1. B) Parallax

3. D) Apparent brightness and distance to the star

4. A) Red giant

5. B) Blue

Explanation:

1. In order to measure the distance to a nearby star, astronomers use parallax method. In this method, parallax angle is measured. The star appears to move against a fixed background when viewed from two different position of Earth in its orbit.

d=\frac{1}[p}

where, <em>d</em> is the distance in parsecs and <em>p</em> is the parallax angle in arc-second.

2. Luminosity of a star is the energy emitted by a star's surface. It measured in watts. In order to measure the luminosity of a star, apparent brightness (b) and distance to the star (d) is required. Following formula can be used to measure the luminosity of a star:

L = 4\pi d^2b

3. The H-R diagram is the plot of stars based on their luminosity, color and temperature. In the upper right of the H-R diagram, red giants are located. These are the cool and bright stars. An average mass star like the sun expands and becomes a red giant when it runs off its fuel before ending up as a white dwarf.

4. Color of a star indicated its surface temperature. A star emits different wavelengths but a peak wavelength can be observed from its spectrum which indicates the star's effective temperature. So, cool stars are red in color where as hot and bright stars are blue in color.

Tema [17]3 years ago
5 0
1) D 3) A 4) A 5) A your welcome hopefully it helped
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Answer:

Magnetic dipole moment is 0.0683 J/T.

Explanation:

It is given that,

Length of the rod, l = 7.3 cm = 0.073 m

Diameter of the cylinder, d = 1.5 cm = 0.015 m

Magnetization, M=5.3\times 10^3\ A/m

The dipole moment per unit volume is called the magnetization of a magnet. Mathematically, it is given by :

M=\dfrac{\mu}{V}

\mu=M\times \pi r^2\times l

Where

r is the radius of rod, r = 0.0075 m

\mu=5.3\times 10^3\ A/m\times \pi (0.0075)^2\times 0.073\ m

\mu=0.0683\ J/T

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A circuit contains two resistors in series. The voltage drop across the first is 10 V. The voltage drop across the second is als
Norma-Jean [14]

Hi there!

Voltage in a series can be expressed by the following:

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tamaranim1 [39]

Answer:

A. 181.24 N

Explanation:

The magnitude of hte electrostatic force between two charged objects is given by the equation

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where

k is the Coulomb's constant

q1, q2 are the magnitudes of the two charges

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In this problem, we have:

q_1=4.5\mu C=4.5\cdot 10^{-6}C is the magnitude of the 1st charge

q_2=2.8\mu C=2.8\cdot 10^{-6}C is the magnitude of the 2nd charge

r = 2.5 cm = 0.025 m is the separation between the charges

Therefore, the magnitude of the electric force is:

F=\frac{(9\cdot 10^9)(4.5\cdot 10^{-6})(2.8\cdot 10^{-6})}{(0.025)^2}=181.44 N

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Answer:

We know that force applied per unit area is called pressure.

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A2 = 10 mx 5 m = 50 Square meter

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