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Genrish500 [490]
4 years ago
5

A. The distance to a star is approximately 8.58 ✕ 10^18 m. If this star were to burn out today, in how many years would we see i

t disappear?
b. How long does it take sunlight to reach Earth?
c. How long does it take for a microwave radar signal to travel from Earth to the Moon and back?
Physics
1 answer:
Tamiku [17]4 years ago
7 0

Answer:

906.27931 years

8.34 minutes

2.56266 seconds

Explanation:

v = Velocity of light = 3\times 10^8\ m/s

s = Distance

Time is given by

t=\dfrac{s}{v}\\\Rightarrow t=\dfrac{8.58\times 10^{18}}{3\times 10^8\times 365.25\times 24\times 3600}\\\Rightarrow t=906.27931\ years

We would see the star disappear after 906.27931 years after it actually disappeared.

Distance between Earth and Sun = 150.18 billion m

t=\dfrac{150.18\times 10^9}{3\times 10^8\times 60}\\\Rightarrow t=8.34\ minutes

It takes 8.34 minutes for sunlight to reach Earth.

Distance between Earth and Moon = 384.4 million m

t=\dfrac{2\times 384.4\times 10^6}{3\times 10^8}\\\Rightarrow t=2.56266\ s

It takes 2.56266 seconds for a microwave radar signal to travel from Earth to the Moon and back.

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An unstrained horizontal spring has a length of 0.26 m and a spring constant of 180 N/m. Two small charged objects are attached
MakcuM [25]

Answer:

a)

two like charges always repel each other while two unlike charges attract each other. Since the spring stretches by 0.039 m, the charges have the same sign. both charges are positive(+) or Negative (-)

b)

both q1 and q1 are 8.35 × 10⁻⁶ C or -8.35 × 10⁻⁶ C

Explanation:

Given that;

L = 0.26 m

k = 180 N/m

x = 0.039 m

a)

we know that two like charges always repel each other while two unlike charges attract each other. Since the spring stretches by 0.039 m, the charges have the same sign.

b)

Spring force F = kx

F = 180 × 0.039

F = 7.02 N

Now, Electrostatic force F = Keq²/r²

where r = L + x = ( 0.26 + 0.039 )

we know that proportionality constant in electrostatics equations Ke = 9×10⁹ kg⋅m3⋅s−2⋅C−2

so from the equation; F = Keq²/r²

Fr² = Keq²

q = √ ( Fr² / Ke )

we substitute

q = √ ( 7.02 N × ( 0.26 + 0.039 )² / 9×10⁹ )

q = √ ( 7.02 N × ( 0.26 + 0.039 )² / 9×10⁹ )

q =  √ (0.627595 / 9×10⁹)

q = √(6.97 × 10⁻¹¹)

q = 8.35 × 10⁻⁶ C

Therefore both q1 and q1 are 8.35 × 10⁻⁶ C or -8.35 × 10⁻⁶ C

5 0
3 years ago
A 90 kg person stands at the edge of a stationary children's merry-go-round at a distance of 5.0 m from its center. The person s
Paraphin [41]

Answer:

\omega = 0.016\,\frac{rad}{s}

Explanation:

The rotation rate of the man is:

\omega = \frac{v}{R}

\omega = \frac{0.80\,\frac{m}{s} }{5\,m}

\omega = 0.16\,\frac{rad}{s}

The resultant rotation rate of the system is computed from the Principle of Angular Momentum Conservation:

(90\,kg)\cdot (5\,m)^{2}\cdot (0.16\,\frac{rad}{s} ) = [(90\,kg)\cdot (5\,m)^{2}+20000\,kg\cdot m^{2}]\cdot \omega

The final angular speed is:

\omega = 0.016\,\frac{rad}{s}

3 0
3 years ago
Increasing the concentration of greenhouse gases in Earth's atmosphere decreases the transparency of the atmosphere to infrared
kondaur [170]

Answer:

Decreases the transparency of the atmosphere to infrared light.

Explanation:

When a large amount of green-house gases are present in the atmosphere, the layer of these gases become opaque to infrared radiation and radiation from the sun get trapped into these gases molecules. These excited molecules radiate this energy into our own atmosphere and that why the temperature of Earth is rising due to the Green-House effect.

8 0
3 years ago
Help Please!!!!!!!!!!!!!!!!!!
julia-pushkina [17]
The answer is 59.4 degrees.
4 0
3 years ago
10. A cyclist travels at 15m/s for 4 minutes. How far does she go?
stiks02 [169]

Answer:

speed = <u>distance</u>

time

15 = <u>X</u>

4

15 × 4 = 60

3 0
4 years ago
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