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3 years ago

The greenhouse effect: select one:

1 answer:

6 0

The greenhouse effect is a natural phenomenon that enables life to propagate in Earth. During the day, the Sun provides energy through sunlight. Note that the Sun's energy is obtained from the nuclear fusion of hydrogen to helium. So, sunlight contains radiation at very high temperatures. In order to regulate heat, the atmosphere allows only some of the heat to be absorbed into the surroundings, but blocking the rest and reflecting it back to space. During night time, without the Sun giving energy, greenhouse gases in the atmosphere has 'reserved' heat that is trapped in the atmosphere. So, the greenhouse gases (like water vapor and carbon dioxide) maintains the average temperature of the Earth's atmosphere at around 33°C.

Therefore, the answer is letter B.

You might be interested in

What is the difference between amplitude and wavelength?

jasenka [17]

Answer:

Letter b is wavelength. Letter a is amplitude.

Explanation:

Let's imagine a simple experiment. Imagine you have a long thick rope which one end is at your hands, and you start an oscillatory motion in it, moving your hand up and down. Then a friend of you take a picture of the rope in motion, looking at the rope laterally. Now let's find the wavelength and amplitude. Amplitude is "The distance from the center of the oscillation of the rope (when the rope was not in motion) to its high or low point", or the vertical displacement, in our experiment. On the other hand, wavelength is "The distance between one high point /low point and the next high point /low point". Take a look at a photo of a wave in your textbook and you will find the answer as well. ; )

3 0

3 years ago

The space shuttle orbits 310 km above the surface of the Earth.

MAVERICK [17]

Answer:

44.7 N

Explanation:

The gravitational force between the objects is given by:

$F=G\frac{mM}{r^2}$

where

G is the gravitational constant

m and M are the masses of the two objects

r is the distance between the centres of the two objects

In this problem, we have:

$m=5.0 kg$ is the mass of the sphere

$M=5.98\cdot 10^{24} kg$ is the Earth's mass

$R=6370 km$ is the Earth's radius, while h=310 km is the altitude of the sphere, so the distance of the sphere from Earth's centre is

$r=6370 km+310 km=6680 km=6.68\cdot 10^6 m$

Substituting into the equation, we find

$F=(6.67\cdot 10^{-11})\frac{(5.0 kg)(5.98\cdot 10^{24} kg)}{(6.68\cdot 10^6 m)^2}=44.7 N$

8 0

3 years ago

A man of mass 70 kg climbs stairs of vertical height 2.5m. Calculate the work done against the force of gravity. (Take g = 9.81

Alona [7]

Answer:

1716.75 J

Explanation:

Step 1: First check what we are provided with. As per given question we have:

mass (m) = 70 kg, height (h) = 2.5 m and acceleration due to gravity (g) = 9.81 m/s².

Step 2: Check what we are asked to find out.

Work done = Change in Potential energy

The stuff required to solve this question is potential energy. Using the formula: P = mgh. Where P is Potential energy, m is mass, g is acceleration due to gravity and h is height.

Step 3: Substitute the known values in the above formula.

→ P = 70 × 2.5 × 9.81

→ P = 1716.75 J

Hence, the work done against the force of gravity is 1716.75 J.

3 0

2 years ago

Ehy Newton's law of gravitation also called universal law?

pychu [463]

Answer:

Gravity is a natural phenomenon that causes all massive objects to attract each other. The magnitude or force of this interaction depends on the masses and distance of the bodies. This causes objects to fall toward Earth, for example, and keep satellites and celestial bodies in their orbits, such as the Earth's orbit around the Sun. Gravity also causes the tidal phenomenon.

In physics, gravity can be approximated by Isaac Newton's laws of gravity. Although the accuracy of the law is sufficient, for example, when calculating the orbits of spacecraft, gravity is best described by Albert Einstein’s general theory of relativity, in which it is considered the curvature of space-time.

7 0

3 years ago

Lified True or False

Nana76 [90]

Trueeeeeeeeeeeeeeeeeeeeeee

5 0

3 years ago