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3 years ago

Discuss how we are able to feel the sun's heat and see its brightness?

2 answers:

8 0

The sun makes so much energy that we are able to see the sun's brightness and feel its heat. Hydrogen fusion occurs in the Sun's core and the gas is heated by the energy that is released above the core. Eventually, the gas becomes less dense and the heat from below turns the gas buoyant

vaieri [72.5K]3 years ago

7 0

Answer:

Sun is bright because it is closer to the earth and the radiation that reaches the earth's surface gives out the heat.

Explanation:

The thermonuclear fusion reactions are responsible for the heat and light emitted by any star.

As a result of the fusion reactions that occur in its core, sun's core is very very hot. This heat is radiated outward and after passing through several zones of the sun itself, the surface temperature of the Sun cools to about about 6000 K.

Sun radiates electromagnetic radiation that can travel through space and then penetrate the earth's atmosphere. Ozone layer which is present in the ozonosphere of the earth's atmosphere filters the UV rays coming from the sun. The radiation in the form of heat and light is absorbed by the particles of air in the earth's atmosphere, there by heating the surface.

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You leave on a 450 miles trip in order to attend a meeting that will start 10.8 hours after you begin your trip. Along the way y

konstantin123 [22]

Answer:

c. 2.6 h

Explanation:

The longest time spent over dinner is the time that you have available minus the minimum possible time spent in the trip.

The time of the trip is found using:

t = $\frac{d}{v}$

Where distance is d and velocity is v. The time will be minimum at maximum velocity. Replacing with the data we have:

Ttrip = $\frac{450}{55}$ = 8.1818 h

Tdinner = 10.8h - 8.1818 h = 2.6181h

that aproximates 2.6 h.

4 0

3 years ago

A navy diver hears the underwater sound wave from an exploding ship across the harbor. They immediately lift their head out of t

tamaranim1 [39]

Answer:

s = 1800 m = 1.8 km

Explanation:

The distance, the speed, and the time of reach of the sound are related by the following formula:

$s = vt$

where,

s = distance

v = speed

t = time

FOR WATER:

$s = v_wt$ ---------------------- eq (1)

where,

s = distance between ship and diver = ?

$v_w$ = speed of sound in water = 1440 m/s

t = time taken by sound in water

FOR AIR:

$s = v_a(t+4\ s)$ ---------------------- eq (2)

where,

s = distance between ship and diver = ?

$v_a$ = speed of sound in water = 344 m/s

t + 4 s = time taken by sound in water

Comparing eq (1) and eq (2),because distance remains constant:

$v_wt=v_a(t+4\ s)\\\\(1440\ m/s)t = (344\ m/s)(t+4\ s)\\(1440\ m/s - 344\ m/s)t=1376\ m\\t = \frac{1376\ m}{1096\ m/s}$

t = 1.25 s

Now using this value in eq (1):

$s = (1440\ m/s)(1.25\ s)$

4 0

3 years ago

At a certain point in space, there is a potential of 800 V relative to zero. What is the potential energy of the system when a +

sammy [17]

To solve this problem we will apply the concepts related to electric potential and electric potential energy. By definition we know that the electric potential is determined under the function:

$V = \frac{k_e q}{r}$

$k_e$ = Coulomb's constant

q = Charge

r = Radius

At the same time

$U = \frac{k_e q_1q_2}{r}$

The values of variables are the same, then if we replace in a single equation we have this expression,

$U = Vq$

If we replace the values, we have finally that the charge is,

$V = 800V$

$q = 1\mu C$

$U = (800V)(1*10^{-6}C)$

$U = 8*10^{-4}J$

Therefore the potential energy of the system is $8*10^{-4} J$

7 0

3 years ago

Find the speed required to throw a ball straight up and it return 6 seconds later. Neglect air resistance

Nadya [2.5K]

Answer:

the ball will go up 3s and down 3s

v=gt

where t=3s and g=9.8m/s^2

distance=v0(t)+(1/2)gt^2

where initial velocity (v0)=0

Explanation:

8 0

3 years ago

A fiber-optic cable (n = 1.53) is submerged in water (n = 1.33). Predict whether light will be refracted or whether it will unde

Aleks [24]

Total internal refraction occurs when a ray of light meets the following conditions.
1. light falls from an optically dense material to a less dense material.
2. The angle of incident in the denser media must be greater than the critical angle.

In the case above the fiber-optic is optically denser than water. Since the light is incident to fiber-optic-water interface, then one condition is fulfilled.
Checking the other condition we carry out the calculation below;

n1sinФ1=n2sinФ2
where c ⇒critical angle
1.53 sinc = 1.33 sin 90
sinc =0.86928
c = 60.37°

The angle of incident is (65°-70°) is greater than critical angle.
With certainty, there would be no refraction. Total internal reflection would occur.

7 0

4 years ago