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4 years ago

Do stars that look brighter in the sky have larger or smaller magnitudes than fainter stars?

Physics

1 answer:

alina1380 [7]4 years ago

8 0

Answer:

Stars that have lower apparent magnitudes have more brightness.

Explanation:

Greek astronomer Hipparchus devised a system of arranging the luminosity of stars with their apparent magnitude. The brightest stars were in the first magnitude class, and the dimmer stars were in the latter magnitude classes.

Later in the 19th century technology had developed to accurately measure a star's brightness. It was established that a factor of exactly 100 times in intensity was due to difference of 5 magnitudes.

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A particle is located on the x axis 4.9 m from the origin. A force of 38 N, directed 30° above the x axis in the x-y plane, acts

Juli2301 [7.4K]

Answer:

Torque is 93 Nm anticlockwise.

Explanation:

We have value of torque is cross product of position vector and force vector.

A force of 38 N, directed 30° above the x axis in the x-y plane.

Force, F = 38 cos 30 i + 38 sin 30 j = 32.91 i + 19 j

A particle is located on the x axis 4.9 m and we have to find torque about the origin on the particle.

Position vector, r = 4.9 i

Torque, T = r x F = 4.9 i x (32.91 i + 19 j) = 4.9 x 19 k = 93.1 k Nm

So Torque is 93 Nm anticlockwise.

7 0

3 years ago

A plane flies from alphaville to betaville and then back to alphaville. when there is no wind, the round trip takes 4 hours and

kykrilka [37]

Refer to the diagram shown below.

d = distance (miles) from Alphaville to Betaville.
v = speed (mph) of the plane with no wind.

With no wind:
The time taken to travel a distance of 2d is 4 hrs, 48 min = 4.8 hrs.
Therefore
2d/v = 4.8
v = 2d/4.8 = 0.4167d mph (1)

With the wind:
The velocity from Alphaville to Betaville is (v + 100) mph.
The time of travel is
t₁ = d/(v+100) h
The velocity from Betaville to Alphaville is (v - 100) mph.
The time of travel is
t₂ = d/)v-100) h
Because the return trip takes 5 hours, therefore
t₁ + t₂ = 5
$\frac{d}{v+100} + \frac{d}{v-100} =5 \\ \frac{2vd}{v^{2}-100^{2}} =5 \\ 2vd = 5(v^{2}-10^{4})$ (2)

From (1), obtain
2(0.4167)d² = 5[(0.4167d)² - 10⁴]
0.8334d² = 0.8682d² - 5 x 10⁴
0.0348d² = 5 x 10⁴
d = 1198.7 mi

Answer: 1199 miles (nearest integer)

8 0

4 years ago

A 25 N force pushes a block across a surface for 6 m.How much work is done by the applied force?

hram777 [196]

Answer: 150 joules

Explanation:

Force applied on a block = 25N

Distance moved by block = 6 m

Workdone = ?

Recall that work is done when force is applied on an object over a distance. And it is measured in joules.

I.e Workdone = Force X Distance

= 25N x 6 metres

= 150 joules

Thus, 150 joules of work is done by the applied force.

4 0

4 years ago

A capacitor is connected to an AC generator. As the generator's frequency is increased, what happens to the current in the capac

Licemer1 [7]

Answer:

The current increases.

Explanation:

A capacitor can be defined as an electronic component used in electrical circuits to store charge temporarily.

A capacitor is connected to an AC generator. As the generator's frequency is increased, the current in the capacitor increases as well.

This ultimately implies that, when a capacitor is connected to an AC generator, the frequency of the circuit is directly proportional to the amount of current flowing through it.

8 0

4 years ago

What type of ethic is life-centered and views humans as just one component life on Earth

katrin [286]

The choices can be found elsewhere and as follows:

A anthropocentric

B frontier

C land

D biocentric

I think the correct answer is option A. It is anthropocentric the type of ethic that is life-centered and views humans as just one component life on Earth. Hope this answers the question. Have a nice day.

4 0

3 years ago

Read 2 more answers