1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kifflom [539]
2 years ago
11

The brightness of a star depends on its (color, composition of atmosphere, or distance from earth), and stars that are closer lo

ok (brighter, dimmer, or white).
Physics
2 answers:
PolarNik [594]2 years ago
5 0

Answer:

Distance, Brighter

Explanation:

Think of a flash light, one close and one far which is brighter and which is dimmer.  

Hope this is what your teacher put as the answer!

seraphim [82]2 years ago
5 0

Answer:

Distance, brighter  

Explanation:

Brightness depends upon the amount of power that is radiated by a star

This in turn follows the inverse square law. That is, as the distance from the object increases, brightness decreases as the square of the distance.

Color depends on the composition of the star's radiation.

When the stars are bright, it can be understood that they are closer, compared to other stars.

You might be interested in
What is the ionisation energy of an atom
V125BC [204]

Explanation:

its the minimum amount of energy required to remove the most loosely bound electron

8 0
3 years ago
Read 2 more answers
Which of the following methods of improving air quality does not require advanced technology?
Kisachek [45]
Conservation is a method of improving air quality
3 0
3 years ago
What term was used to describe the final digit
xxMikexx [17]

Answer:

Significant digits (also called significant figures or “sig figs” for short) indicate the precision of a measurement. A number with more significant digits is more precise. For example, 8.00 cm is more precise than 8.0 cm.

7 0
2 years ago
A flywheel is a mechanical device used to store rotational kinetic energy for later use. Consider a flywheel in the form of a un
Kamila [148]

Answer:

<em>a) 6738.27 J</em>

<em>b) 61.908 J</em>

<em>c)  </em>\frac{4492.18}{v_{car} ^{2} }

<em></em>

Explanation:

The complete question is

A flywheel is a mechanical device used to store rotational kinetic energy for later use. Consider a flywheel in the form of a uniform solid cylinder rotating around its axis, with moment of inertia I = 1/2 mr2.

Part (a) If such a flywheel of radius r1 = 1.1 m and mass m1 = 11 kg can spin at a maximum speed of v = 35 m/s at its rim, calculate the maximum amount of energy, in joules, that this flywheel can store?

Part (b) Consider a scenario in which the flywheel described in part (a) (r1 = 1.1 m, mass m1 = 11 kg, v = 35 m/s at the rim) is spinning freely at its maximum speed, when a second flywheel of radius r2 = 2.8 m and mass m2 = 16 kg is coaxially dropped from rest onto it and sticks to it, so that they then rotate together as a single body. Calculate the energy, in joules, that is now stored in the wheel?

Part (c) Return now to the flywheel of part (a), with mass m1, radius r1, and speed v at its rim. Imagine the flywheel delivers one third of its stored kinetic energy to car, initially at rest, leaving it with a speed vcar. Enter an expression for the mass of the car, in terms of the quantities defined here.

moment of inertia is given as

I = \frac{1}{2}mr^{2}

where m is the mass of the flywheel,

and r is the radius of the flywheel

for the flywheel with radius 1.1 m

and mass 11 kg

moment of inertia will be

I =  \frac{1}{2}*11*1.1^{2} = 6.655 kg-m^2

The maximum speed of the flywheel = 35 m/s

we know that v = ωr

where v is the linear speed = 35 m/s

ω = angular speed

r = radius

therefore,

ω = v/r = 35/1.1 = 31.82 rad/s

maximum rotational energy of the flywheel will be

E = Iw^{2} = 6.655 x 31.82^{2} = <em>6738.27 J</em>

<em></em>

b) second flywheel  has

radius = 2.8 m

mass = 16 kg

moment of inertia is

I = \frac{1}{2}mr^{2} =  \frac{1}{2}*16*2.8^{2} = 62.72 kg-m^2

According to conservation of angular momentum, the total initial angular momentum of the first flywheel, must be equal to the total final angular momentum of the combination two flywheels

for the first flywheel, rotational momentum = Iw = 6.655 x 31.82 = 211.76 kg-m^2-rad/s

for their combination, the rotational momentum is

(I_{1} +I_{2} )w

where the subscripts 1 and 2 indicates the values first and second  flywheels

(I_{1} +I_{2} )w = (6.655 + 62.72)ω

where ω here is their final angular momentum together

==> 69.375ω

Equating the two rotational momenta, we have

211.76 = 69.375ω

ω = 211.76/69.375 = 3.05 rad/s

Therefore, the energy stored in the first flywheel in this situation is

E = Iw^{2} = 6.655 x 3.05^{2} = <em>61.908 J</em>

<em></em>

<em></em>

c) one third of the initial energy of the flywheel is

6738.27/3 = 2246.09 J

For the car, the kinetic energy = \frac{1}{2}mv_{car} ^{2}

where m is the mass of the car

v_{car} is the velocity of the car

Equating the energy

2246.09 =  \frac{1}{2}mv_{car} ^{2}

making m the subject of the formula

mass of the car m = \frac{4492.18}{v_{car} ^{2} }

3 0
3 years ago
The de broglie wavelength of a ________ will have the shortest wavelength when traveling at 30 cm/s.
Airida [17]

Answer: H/MV

Explanation:

5 0
3 years ago
Read 2 more answers
Other questions:
  • Third-largest ocean?
    11·2 answers
  • How to type a capital letter in my computer​
    9·2 answers
  • What is the average velocity of a dragster that starts from rest at the starting line and finishes a race at 2600 m/s in 12 seco
    7·1 answer
  • A train travels 98 kilometers in 1 hours, and then 78 kilometers in 3 hours. what is its average speed?
    14·1 answer
  • Most people would consider a comfortable room temperature to be
    11·2 answers
  • An experiment based at New Mexico’s Apache Point observatory uses a laser beam to measure the distance to the Moon with millimet
    13·1 answer
  • Is the normal force equivalent to the weight of an object?
    13·1 answer
  • Which is the correct procedure to determine the daily mean temperature?.
    15·1 answer
  • The potential energy for a mass on a spring is proportional to the square of which of these quantities?
    7·1 answer
  • Which trait shared by dolphins and bats possibly lead to the evolution of echolocation in these two animal groups? the need to m
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!