All categories

4 years ago

Why is the spectrum of a star called an absorption spectrum?

1 answer:

6 0

It is called absorption spectrum because a gas of hydrogen will make a line spectrum and if viewed for another angle it would be between a continuum light and a emission line spectrum

You might be interested in

Which was not a feature of the northwest ordinance of 1787

Tamiku [17]

What are the choices?

4 0

4 years ago

Determine the average distance between the Earth and the Sun. Then calculate the average speed of the Earth in its orbit in kilo

FrozenT [24]

Answer:

The average speed of the Earth in its orbit is 4.74 km/s.

Explanation:

Distance between the Earth and the Sun ,r= 149.60 million km = $149.60\times 10^6 km$

Considering the movement of Earth around the Sun follows circular path.

The circumference of circular path will be give by :

$D=2\pi r=2\times 3.14\times 149.60\times 10^6 km$

Time taken by Earth to complete revolution around earth ,T= 1 year

1 year = 365 days

1 year = 31,536,000 seconds

T = 31,536,000 seconds

Speed of the Earth around the Sun :S

$S=\frac{D}{T}=\frac{149.60\times 10^6 km}{31,536,000 s}$

$S=4.74 km/s$

The average speed of the Earth in its orbit is 4.74 km/s.

8 0

3 years ago

A recent home energy bill indicates that a household used 475475 kWh (kilowatt‑hour) of electrical energy and 135135 therms for

faltersainse [42]

Answer:

Explanation:

Given that,.

A house hold power consumption is

475 KWh

Gas used is

135 thermal gas for month

Given that, 1 thermal = 29.3 KWh

Then,

135 thermal = 135 × 29.3 = 3955.5 KWh

So, total power used is

P = 475 + 3955.5

P =4430.5 KWh

Since 1 hr = 3600 seconds

So, the energy consumed for 1hr is

1KW = 1000W

P = energy / time

Energy = Power × time

E = 4430.5 KWhr × 1000W / KW × 3600s / hr

E = 1.595 × 10^10 J

So, using Albert Einstein relativity equation

E = mc²

m = E / c²

c is speed of light = 3 × 10^8 m/s

m = 1.595 × 10^10 / (3 × 10^8)²

m = 1.77 × 10^-7 kg

Then,

1 kg = 10^6 mg

m = 1.77 × 10^-7 kg × 10^6 mg / kg

m = 0.177mg

m ≈ 0.18 mg

5 0

3 years ago

Examples of Cardiovascular Endurance ( check all that apply)

sveta [45]

Answer:

Cardiorespiratory endurance is the level at which your heart, lungs, and muscles work together when you're exercising for an extended period of time.

...

Other activities
running or jogging.
swimming.
cycling.
dancing.
boxing.
aerobics or similar activities.
any active sport.

7 0

3 years ago

Two massless bags contain identical bricks, each brick having a mass M. Initially, each bag contains four bricks, and the bags m

stepladder [879]

Answer: $F_{2}=\frac{3}{4}F_{1}$

Explanation:

According to Newton's law of universal gravitation:

$F=G\frac{m_{1}m_{2}}{r^2}$

Where:

$F$ is the module of the force exerted between both bodies

$G$ is the universal gravitation constant.

$m_{1}$ and $m_{2}$ are the masses of both bodies.

$r$ is the distance between both bodies

In this case we have two situations:

1) Two bags with masses $4M$ and $4M$ mutually exerting a gravitational attraction $F_{1}$ on each other:

$F_{1}=G\frac{(4M)(4M)}{r^2}$ (1)

$F_{1}=G\frac{16M^2}{r^2}$ (2)

$F_{1}=16\frac{GM^2}{r^2}$ (3)

2) Two bags with masses $2M$ and $6M$ mutually exerting a gravitational attraction $F_{2}$ on each other (assuming the distance between both bags is the same as situation 1):