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2 years ago

Which of the following is the best thermal insulator?

Physics

2 answers:

Mama L [17]2 years ago

5 0

Answer: A. Air

Explanation: Air is a poor thermal conductor because it's particles are farther apart.

serious [3.7K]2 years ago

3 0

Answer:

A. Air

Explanation:

A thermal insulator is a material that does not let the heat trasmitting through it, or it transmits heat not very efficiently.

Generally, the lower the density of the material, the better insulator the material is: this is because in materials with very low density, particles are very spread apart, so they cannot collide with each other, and so the vibrations of the particles (which determine how hot a substance is) cannot be transmitted very efficiently.

In the options listed in this problem, air is the material with lowest density, therefore it is the best thermal insulator among them.

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How are the climates of coastal regions affected by the specific heat capacity of water?

Katen [24]

Answer:

The specific heat capacity can be defined as the amount of heat required to raise the temperature of 1 unit of mass by 1 unit temperature. The specific heat capacity of water is 4.186 joule/gram °C which is higher than common substances. The land has lower specific heat capacity. Thus, the land gets hot quickly than water.

This results in warming up air near the land which creates a difference in pressure across the coastal region. Sea breeze blows from sea towards landmass. Opposite happens at night, when water is still warm and land gets cooled down quickly. Then land breeze blows from landmass towards the sea. This breeze maintains a moderate temperature and windy and humid weather in the coastal regions.

5 0

3 years ago

A 38.5kg man is in an elevator accelerating downward. A normal force of 343n pushes up on him. what is his acceleration?

alexira [117]

Answer:

<h3>The answer is 8.91 m/s²</h3>

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

$a = \frac{f}{m} \\$

f is the force

m is the mass

From the question we have

$a = \frac{343}{38.5} = \frac{98}{11} \\ = 8.909090...$

We have the final answer as

Hope this helps you

4 0

2 years ago

Calculate the kinetic energy of a 0.032 kg ball as it leaves a hand to be thrown upwards at 6.2 m/s

AnnZ [28]

Answer:

The ball will have a kinetic energy of 0.615 Joules.

Explanation:

Use the kinetic energy formula

$E_k = \frac{1}{2}mv^2 = \frac{1}{2}0.032kg\cdot 6.2^2 \frac{m^2}{s^2}= 0.615J$

The kinetic energy at the moment of leaving the hand will be 0.615 Joules. (From there on, as it ball is traveling upwards, this energy will be gradually traded off with potential energy until the ball's velocity becomes zero at the apex of the flight)

3 0

3 years ago

a runner increases her speed from 3.1 m/s to 3.5 m/s during the last 15 seconds of her run, what was her acceleration during her

Rama09 [41]

Acceleration = velocity/time
A= 3.5m/s/15s
A= 0.23m/s^2

5 0

3 years ago

Read 2 more answers

A toroidal solenoid with mean radius r and cross-sectional area A is wound uniformly with N1 turns. A second toroidal solenoid w

lilavasa [31]

Answer:

Mutual inductance, $M=2.28\times 10^{-5}\ H$

Explanation:

(a) A toroidal solenoid with mean radius r and cross-sectional area A is wound uniformly with N₁ turns. A second thyroidal solenoid with N₂ turns is wound uniformly on top of the first, so that the two solenoids have the same cross-sectional area and mean radius.

Mutual inductance is given by :

$M=\dfrac{\mu_oN_1N_2A}{2\pi r}$