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3 years ago

When a perfume bottle is opened, some liquid changes to gas and the fragrances spreads around the room.

1 answer:

8 0

The liquid changes to gas by the process of 'vaporization' or 'evaporation.
The gas spreads around the room by the process of 'diffusion'.

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How can I find the vertical velocity

Rufina [12.5K]

Answer:

The final vertical velocity is given by Equation

Explanation:

5 0

3 years ago

A boat moves at 10.8 m/s relative to the water. If the boat is in a river where the current is 2.00 m/s, how long does it take t

Ray Of Light [21]

Answer:

Option E is the correct answer.

Explanation:

Velocity of boat = 10.8 m/s

Velocity of river = 2 m/s

Relative velocity upstream = 10.8 - 2 = 8.8 m/s

Displacement = Velocity x Time

1100 = 8.8 x t₁

Time in upstream, t₁ = 125 s

Relative velocity downstream = 10.8 + 2 = 12.8 m/s

Displacement = Velocity x Time

1100 = 12.8 x t₂

Time in downstream, t₂ = 86 s

Total time = t₁ + t₂ = 125 + 86 = 211 s

Option E is the correct answer.

8 0

3 years ago

April stands on a flat surface. if she has a mass of 72 kg, what is the normal

klio [65]

N=m.g

N=72 x 9.8 = 705.6 ≈ 706 N

7 0

2 years ago

A series of lines involving a common level in the spectrum of atomic hydrogen lies at 656.46 nm, 486.27 nm, 434.17 nm, and 410.2

julsineya [31]

Answer:

The wavelength of next line in the series will be 397.05 nm

Explanation:

From Rydberg equation;

$\frac{1}{\lambda} = R_H(\frac{1}{n_1^2} -\frac{1}{n_2^2})$

where;

λ is the wavelength

n lines in the series

RH is Rydberg constant = 1.097 x 10⁷ m⁻¹

Also at a given maximum wavelength, we can determine the first line n₁ in the series

$\frac{1}{\lambda_{max}R_H} = \frac{1}{n_1^2} -\frac{1}{(n_1 +1)^2} \\\\$

$\frac{1}{\lambda_{max}R_H} = \frac{2n_1+1}{n_1^2(n_1 +1)^2} \\\\\lambda_{max}R_H} = \frac{n_1^2(n_1 +1)^2}{2n_1+1}$

Given;

maximum wavelength = 656.46 nm

$\lambda_{max}R_H} = \frac{n_1^2(n_1 +1)^2}{2n_1+1}\\\\656.46 *10^{-9}*1.097*10^7 = \frac{n_1^2(n_1 +1)^2}{2n_1+1}\\\\7.2 = \frac{n_1^2(n_1 +1)^2}{2n_1+1}$

Now, test for different values of n that will be equal to 7.2

let n₁ = 1

$\frac{n_1^2(n_1 +1)^2}{2n_1+1} = \frac{(1)^2(1 +1)^2}{2(1)+1} = 1.3\\$

n₁(1) ≠ 7.2

Again, let n₁ = 2

$\frac{n_1^2(n_1 +1)^2}{2n_1+1} = \frac{(2)^2(2 +1)^2}{2(2)+1} = 7.2\\$

∴ n₁(2) = 7.2

For the least wavelength given as 410.29 nm, n = ?

$\frac{1}{\lambda} = R_H(\frac{1}{n_1^2} -\frac{1}{n_2^2})\\\\\frac{1}{410.29*10^{-9}} = 1.097*10^7(\frac{1}{2^2} -\frac{1}{n_2^2})\\\\\frac{1}{4.5} =\frac{1}{4} -\frac{1}{n_2^2}\\\\\frac{1}{n_2^2} =\frac{1}{4} -\frac{1}{4.5} \\\\\frac{1}{n_2^2} = 0.0277778\\\\n_2^2 = \frac{1}{0.0277778} \\\\n_2^2 = 36\\\\n_2= \sqrt{36}\ = 6$

next line in the series will be 7

The wavelength of next line in the series will be;

$\frac{1}{\lambda} = R_H(\frac{1}{n_1^2} -\frac{1}{n_2^2})\\\\\frac{1}{\lambda} = 1.097*10^7(\frac{1}{2^2} -\frac{1}{7^2})\\\\\frac{1}{\lambda} = 1.097*10^7(0.22959)\\\\\frac{1}{\lambda} = 2518602.3\\\\\lambda = 397.05 \ nm$

Therefore, the wavelength of next line in the series will be 397.05 nm

5 0

3 years ago

NASA launches a satellite into orbit at a height above the surface of the Earth equal to the Earth's mean radius. The mass of th

Rzqust [24]

Answer:

a) 3h 59’ b) 5,590 m/s c) 1,910 N

Explanation:

The only force acting on the satellite (neglecting the influence of any other body) is just the attractive force from Earth, which is given by the Universal Law of Gravitation:

Fg = G* ms*me / (res² (1)

where: G = 6.67* 10⁻¹¹ N.m² / kg² ms = 780 kg, me= 5.97* 10²⁴ kg, and

res = 2* 6.38* 10⁶ m (distance between the center of the Earth and the satellite).

Fg = 1,910 N (answer c)

At the same time, this force, is the centripetal force that keeps the satellite in orbit, and that can be written as follows:

Fg = ms * v² / res (2)

By definition of velocity, we can say that the constant speed at which the satellite orbits, can be expressed as the quotient between the distance travelled around the Earth once, and the time needed to do that, which is called the period of the orbit:

v = 2*π*res / T (3)

We can solve for v first, taking the right sides of (1) and (2), as follows:

G* ms*me / (res)²= ms * v² / res

v = √(G*me/r) = 5,590 m/s (answer b)

Once obtained the value of v, we can replace in (3), and solve for T:

T = 2* π*res / v = 3 h 59 min (answer a)

7 0

3 years ago