Consider this acid-base reaction:

A star is estimated to be 4.8 km away from the earth. When we see this star in the night sky how old is the image. Let the speed

andre [41]

Time = distance / speed

Time = (4,800 meters) / (3 x 10⁸ m/s)

Time = 0.000016 second

This number is not one of the choices on the list. My hunch is that you copied the distance wrong.

If the estimated distance to the star is actually 4.8 x 10¹⁵ km, instead of 4.8 km, then the answer would be close to 500 years (B).

There's no way a star can be "4.8 km away from the Earth". You can walk that far in about an hour, and passenger jet airplanes fly twice as far as that away from the Earth !

5 0

3 years ago

HURRY!!!!! Which change of state is shown into the model?

nadezda [96]

Option (B) is correct. The process shown in the model is the process of DEPOSITION.

Explanation:

The first container shows the molecules of the substance present inside it at a fairly large distance from one another whereas the second container, the molecules of the substance are very close to each other.

This shows that the substance in the first container is gaseous in nature whereas the substance in the second container is solid in nature as its molecules are closely packed.

Therefore, it shows the phase transition of a substance from gaseous sate to the solid state. The process of conversion of a gas directly into a solid is termed as deposition. This process is the opposite of the Sublimation in which the solid gets directly converted into a gas. Thus, the process is also termed as desublimation.

Thus, Option (B) is correct. The process shown in the model is the process of DEPOSITION.

Learn More:

1. Kinetic energy of a body depends on brainly.com/question/137098

2. X-component of the object's acceleration brainly.com/question/7114558

3. Velocity is a combination of which of the following brainly.com/question/1890447

Answer Details:

Grade: High School

Subject: Physics

Chapter: States of matter

Keywords:

Sublimation, phase transition, solid, gas, molecules, distance, deposition, freezing, boiling, container, second.

7 0

4 years ago

Please do not round the numbers

slamgirl [31]

Answer:

1) λ = 24.7 cm, 2) f = 13.88 Hz, 3) L = 117.3 cm

Explanation:

1) This is a resonance process, that is, the wave going downwards will interfere with the wave going upwards.

This is a tube with one end closed and the other open, at the closed end there is a node and at the open end a belly, so the resonances are

L = λ / 4

λ = 4L 1st harmonic

λ = 4L / 3 third harmonic

λ = 4L / 5 fifth harmonic

λ = 4L / n ’ n’ odd number n ’= (2n +1)

the wavelength is requested for the eighth resonance n = 8, the corresponding prime number is

n ’= 2 8 +1

n ’= 17

we substitute

λ = 4 105/17

λ = 24.7 cm

2) the speed of the wave is related to the wavelength and frequency

v = λf

f = v /λ

f = 343 / 24.7

f = 13.88 Hz

3) the next resonance occurs for n = 9, so the prime number is

n ’= 2 9 +1

n ’= 19

L = n’ λ / 4

L = 19 λ / 4

We must suppose a value for the wavelength, if the wavelength is present in the tube and the length of the column increases, the resonance number increases

L = 19 24.7/4

L = 117.3 cm

8 0

3 years ago

An inclined plane has a velocity ratio of 2 and efficiency of 95%. it is used to raise a load of 400newtons. determine mechanica

Travka [436]

Answer:

1.9

Explanation:

Efficiency=mechanical advantage/velocity ratio×100

95=M.A/2×100

95=50M.A

M.A=95/50=1.9

4 0

3 years ago

2 equal charges are kept at x=a and x=-a. there can be only 1 point where the electric field will be 0? how, can anyone explain?

svet-max [94.6K]

Answer:

At the midpoint of the line joining the two equal charges

Explanation:

The midpoint of the line joining the two equal charges has equal distance from each charge. Since the charges are at x = a and x = -a, at the midpoint of the line joining the two equal charges, the magnitude of the electric field experienced as a result of each charge is the same. But these two fields are in opposite direction, hence the net resulting electric field would be equal to zero.

6 0

3 years ago