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2 years ago

Explain why energy from the sun cannot reach us by conduction or convection?

Physics

2 answers:

34kurt2 years ago

8 0

Answer:

It cannot reach us by conduction or convection as there is no medium such as air in most part of the space between the earth and the sun. From the sun the heat comes to us by another process known as radiation. The transfer of heat by radiation does not require any medium.

k0ka [10]2 years ago

8 0

Answer:

Heat can't be transferred from sun to earth by conduction, because air is a bad conductor of heat. Convection is the transfer of heat in gases & liquids. Convection occurs when a heated fluid moves away from the source of heat and comes in contact with other substances, transferring some of their energy.

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Vsevolod [243]

I believe I seen on google if you go to Mather

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3 years ago

Classify the objects as being magnetic or nonmagnetic.

anygoal [31]

Answer:

Magnetic substances: steel tank, iron ball, nickel hinge

Non magnetic substances: wooden table, glass marbles, silver medal.

Explanation:

The substances which experience a force of attraction when placed in a magnetic field are called magnetic substances. For example, iron, cobalt and nickel.

The substances which do not experiences a force of attraction when placed in a magnetic field are called non magnetic substances. For example, wood, rubber, glass, etc.

8 0

3 years ago

Read 2 more answers

A cylindrical cistern, constructed below ground level, is 2.9 m in diameter and 2.0 m deep and is filled to the brim with a liqu

Tomtit [17]

Answer:

15.1 m

Explanation:

We first calculate the apparent depth from

refractive index, n = real depth/apparent depth

apparent depth, a = real depth/refractive index

real depth = 2.0 m, refractive index = 1.4

apparent depth, a = 2.0/1.4 = 1.43 m

Since the cylindrical cistern has a diameter of 2.9 m, its radius is 2.9/2 = 1.45 m

The angle of refraction, r is thus gotten from the ratio

tan r = radius/apparent depth = 1.45/1.43 = 1.014

r = tan⁻¹(1.014) = 45.4°

The angle of incidence, i is gotten from n = sin i/sin r

sin i = nsin r = 1.4sin45.4° = 1.4 × 0.7120 = 0.9968

i = sin⁻¹(0.9968) = 85.44°

Since the girl's eyes are 1.2 m from the ground, the distance ,h from the edge of the cistern she must stand is gotten from

tan i = h/1.2

h = 1.2tan i = 1.2tan85.44° = 1.2 × 12.54 = 15.05 m

h = 15.05 m ≅ 15.1 m

So, she must stand 15.1 m away from the edge of the cistern to still see the object.

4 0

3 years ago

A 2-kg rock is thrown vertically upward at a speed of 3.2 m/s from the surface of the moon. If it returns to its starting point

worty [1.4K]

Answer:

1.6 m/s2

Explanation:

Let $g_m$ be the gravitational acceleration of the moon. We know that due to the law of energy conservation, kinetic energy (and speed) of the rock when being thrown upwards from the surface and when it returns to the surface is the same. Given that $g_m$ stays constant, we can conclude that the time it takes to reach its highest point, aka 0 velocity, is the same as the time it takes to fall down from that point to the surface, which is half of the total time, or 4 / 2 = 2 seconds.