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Olin [163]
3 years ago
10

if a star is 20 light minutes away and it stops creating light, how long will it be before we stop seeing the light?

Physics
1 answer:
Sloan [31]3 years ago
7 0
20 light minutes
this is because light takes time to travel

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Assume that a lightning bolt can be modeled as a long, straight line of current. If 16 C of charge passes by a point in 1.50 x 1
Reptile [31]

Answer:

B = 7.9012*10^{-5}T

Explanation:

To solve the problem, the concepts related to the magnetic field and the current produced in a lightning bolt are necessary.

The current is defined by the load due to time, that is to say

I= \frac{q}{t}

Where,

q= Charge

t = time

So the current can be expressed as:

I = \frac{16}{1.5*10^{-3}}

I = 10666.67A

Once the current is found it is now possible to find the magnetic field, as this is given by the equation,

B =\frac{\mu_0}{2\pi}\frac{I}{r}

Where,

\mu_0 =Permeability Constant

I= Current

r= radius

Replacing the values we have

B=\frac{4\pi*10^{-7}}{2\pi}(\frac{10666.67}{27})

B = 7.9012*10^{-5}T

7 0
3 years ago
An x-ray beam of wavelength 1.4×10−10m makes an angle of 20° with a set of planes in a crystal(the Bragg angle)causing first ord
Gnom [1K]

Answer:

Second order line appears at 43.33° Bragg angle.

Explanation:

When there is a scattering of x- rays from the crystal lattice and interference occurs, this is known as Bragg's law.

The Bragg's diffraction equation is :

n\lambda=2d\sin\theta      .....(1)

Here n is order of constructive interference, λ is wavelength of x-ray beam, d is the inter spacing distance of lattice and θ is the Bragg's angle or scattering angle.

Given :

Wavelength, λ = 1.4 x 10⁻¹⁰ m

Bragg's angle, θ = 20°

Order of constructive interference, n =1

Substitute these value in equation (1).

1\times1.4\times10^{-10} =2d\sin20

d = 2.04 x 10⁻¹⁰ m

For second order constructive interference, let the Bragg's angle be θ₁.

Substitute 2 for n, 2.04 x 10⁻¹⁰ m for d and 1.4 x 10⁻¹⁰ m for λ in equation (1).

2\times1.4\times10^{-10} =2\times2.04\times10^{-10} \sin\theta_{1}

\sin\theta_{1} =0.68

<em>θ₁ </em>= 43.33°

4 0
2 years ago
A circus act involves a trapeze artist and a baby elephant. They are going to balance on a teeter-totter that is 10 meters long
elena-s [515]

Answer:

Explanation:

Balance point will be achieved as soon as the weight of the baby elephant creates torque equal to torque created by weight of woman about the pivot. torque by weight of woman

weight x distance from pivot

= 500x 5

= 2500 Nm

torque by weight of baby woman , d be distance of baby elephant from pivot at the time of balance

= 2500x d

for equilibrium

2500 d = 2500

d = 1 m

So elephant will have to walk up to 1 m close to pivot or middle point.

6 0
3 years ago
What determines the radiation that an electromagnetic wave emits?
seropon [69]
The question is a little confusing. An electromagnetic wave is radiation. One doesn’t emit the other. Take another look at the question and write it again please.
3 0
3 years ago
Read 2 more answers
A body of mass 2 kg is moving in the positive X-Direction with a speed of 4 m/s collides head on with an another body of mass 3
Inga [223]
m_1=2 \\ m_2=3 \\ v_1=4 \\ v_2=1 \\ v\text{ =speed after collision (to be determined)}.

The momentul of the system preserves:

m_1v_1-m_2v_2=(m_1+m_2)v \ \ \ \ \ \Rightarrow \ \ \ \ \ v=\dfrac{m_1v_1-m_2v_2}{m_1+m_2}.

Ok, we found the speed after the collision.
Now, because the impact is plastic, it produces heat, sound energy and who knows what other forms of energy. We denote all this wasted energy with E.

Now, we write the energy conservation law:

\dfrac{m_1v_1^2}{2}+\dfrac{m_2v^2_2}{2}=\dfrac{(m_1+m_2)v^2}{2}+E

From the above equation, you find E,  and then conclude that the sound energy can certainly not be greater than this.
8 0
3 years ago
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