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2 years ago

5

How long does it take light to reach Earth from an object on light-year away?

1 answer:

stepladder [879]2 years ago

5 0

Answer:

The short answer is that it takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth.

Explanation:

how long does it take sunlight to reach Earth? This sounds like a strange question, but think about it. Sunlight travels at the speed of light. Photons emitted from the surface of the Sun need to travel across the vacuum of space to reach our eyes. If the Sun suddenly disappeared from the Universe (not that this could actually happen, don't panic), it would take a little more than 8 minutes before you realized it was time to put on a sweater.

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Pls help, and thanks if you do!:)

sveta [45]

Protons- 17
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3 0

3 years ago

Read 2 more answers

A bullet with a mass of 14.5 is shot out of a rifle that has a length 1.08. The bullet spends 0.14 on the barreL. What is the ac

Over [174]

Answer:

110 m/s²

Explanation:

Given:

v₀ = 0 m/s

Δx = 1.08 m

t = 0.14 s

Find: a

Δx = v₀ t + ½ at²

1.08 m = (0 m/s) (0.14 s) + ½ a (0.14 s)²

a = 110 m/s²

7 0

2 years ago

3 reasons how scientists evaluate models

tigry1 [53]

Scientists use models to help explain an idea, visualize hypotheses, and closely examine something (such as an atom).

8 0

4 years ago

The mean time between collisions for electrons in room temperature copper is 2.5 x 10-14 s. What is the electron current in a 2

Darya [45]

Answer:

1.87 A

Explanation:

τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s

d = diameter of copper wire = 2 mm = 2 x 10⁻³ m

Area of cross-section of copper wire is given as

A = (0.25) πd²

A = (0.25) (3.14) (2 x 10⁻³)²

A = 3.14 x 10⁻⁶ m²

E = magnitude of electric field = 0.01 V/m

e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C

m = mass of electron = 9.1 x 10⁻³¹ kg

n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³

$i$ = magnitude of current

magnitude of current is given as

$i = \frac{Ane^{2}\tau E}{m}$

$i = \frac{(3.14\times 10^{-6})(8.47\times 10^{28})(1.6\times 10^{-19})^{2}(2.5\times 10^{-14}) (0.01)}{(9.1\times 10^{-31})}$

$i$ = 1.87 A

4 0

3 years ago

Consider the three dip1acement vectors A = (3i - 3j) m, B = (i-4j) m, and C = (-2i + 5j) m. Use the component method to determin

tia_tia [17]

Answer with Explanation:

We are given that

A=3i-3j m

B=i-4 j m

C=-2i+5j m

a. $D=A+B+C$

$D=3i-3j+i-4j-2i+5j$

$D=2i-2j$

Compare with the vector r=xi+yj

We get x=2 and y=-2

Magnitude= $\mid D\mid=\sqrt{x^2+y^2}=\sqrt{(2)^2+(-2)^2}=2\sqrt 2$ units

By using the formula $\mid r\mid=\sqrt{x^2+y^2}$

Direction: $\theta=tan^{-1}\frac{y}{x}$

By using the formula

Direction of D: $\theta=tan^{-1}(\frac{-2}{2})=tan^{-1}(-1)=tan^{-1}(-tan45^{\circ})=-45^{\circ}$

b.E=-A-B+C

$E=-3i+3j-i+4j-2i+5j$

$E=-6i+12j$

$\mid E\mid=\sqrt{(-6)^2+(12)^2}=13.4$ units

Direction of E= $\theta=tan^{-1}(\frac{12}{-6}=tan^{-1}(-2)=-63.4^{\circ}$

4 0

4 years ago