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3 years ago

6

Astronomers use the _ of stars to determine how hot they are and their _ to estimate how far away they are. A. brigh

tness; size B. temperature; position C. size; temperature D. color; brightness

1 answer:

ss7ja [257]3 years ago

6 0

Astronomers use the color of stars to determine how hot they are and their brightness to estimate how far away they are. <em>(D)</em>

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How many atoms are present in 3 molecules of chromium

iren2701 [21]

Answer:

1,8066 x 1024 atoms

Explanation:

1 mole of chromium contains 6,022 x 1023 atoms

so

3 moles of chromium contains 3 times as many atoms

3 x 6,022 x 1023 = 1,8 066 x 1024

5 0

3 years ago

What is the SI unit of electric charge

shusha [124]

Answer:

The SI unit for electric chargeis the C (which is the abbreviation of Coulomb}

Explanation:

The SI unit for electric chargeis the Coulomb. The letter used is the C.

1 C = 1 As

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3 years ago

Two charges of +4x10-SC and -4x10-5C are placed 1 meter apart. Using Coulomb's law, the force between them is 14.4 N.

Snowcat [4.5K]

Answer:

d. the force is reduced by one quarter to 3.6 n

Explanation:

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1 year ago

A block of unknown mass is attached to a spring with a spring constant of 7.00 N/m 2 and undergoes simple harmonic motion with a

KatRina [158]

Answers:

a) $0.80 kg$

b) $2.12 s$

c) $1.093 m/s^{2}$

Explanation:

We have the following data:

$k=7 N/m$ is the spring constant

$A=12.5 cm \frac{1 m}{100 cm}=0.125 m$ is the amplitude of oscillation

$V=32 cm/s=0.32 m/s$ is the velocity of the block when $x=\frac{A}{2}=0.0625 m$

Now let's begin with the answers:

<h3>a) Mass of the block</h3>

We can solve this by the conservation of energy principle:

$U_{o}+K_{o}=U_{f}+K_{f}$ (1)

Where:

$U_{o}=k\frac{A^{2}}{2}$ is the initial potential energy

$K_{o}=0$ is the initial kinetic energy

$U_{f}=k\frac{x^{2}}{2}$ is the final potential energy

$K_{f}=\frac{1}{2} m V^{2}$ is the final kinetic energy

Then:

$k\frac{A^{2}}{2}=k\frac{x^{2}}{2}+\frac{1}{2} m V^{2}$ (2)

Isolating $m$ :

$m=\frac{k(A^{2}-x^{2})}{V^{2}}$ (3)

$m=\frac{7 N/m((0.125 m)^{2}-(0.0625 m)^{2})}{(0.32 m/s)^{2}}$ (4)

$m=0.80 kg$ (5)

<h3>b) Period</h3>

The period $T$ is given by:

$T=2 \pi \sqrt{\frac{m}{k}}$ (6)

Substituting (5) in (6):

$T=2 \pi \sqrt{\frac{0.80 kg}{7 N/m}}$ (7)

$T=2.12 s$ (8)

<h3>c) Maximum acceleration</h3>

The maximum acceleration $a_{max}$ is when the force is maximum $F_{max}$ , as well :

$F_{max}=m.a_{max}=k.x_{max}$ (9)

Being $x_{max}=A$

Hence:

$m.a_{max}=kA$ (10)

Finding $a_{max}$ :

$a_{max}=\frac{kA}{m}$ (11)

$a_{max}=\frac{(7 N/m)(0.125 m)}{0.80 kg}$ (12)

Finally:

$a_{max}=1.093 m/s^{2}$

5 0

2 years ago

if the pressure on a gas increases, the volume of the gas also increases is that statement true or false?

Arada [10]

False, according to Boyle's law it's pressure increases, volume decreases

6 0

3 years ago