What role does density play in the movement of convection curruents?

Physics

1 answer:

shtirl [24]4 years ago

7 0

Convection occurs through heat transfer due to a difference in density in the fluids.

Consider a pot of water being heated. The water in the pot gets heated rises ,it provides energy for the particles in the water to move and thus the water expands which results in the density of the water becoming less. These particles rise up till the top of the pot owing to the property of very less density of the particles.

Then after some time, it cools down which results in increase of the density of the particles. The heavier denser particles sink to the bottom and is once again heated and rises and this process continues unless all the water particles in the pot are heated and warmed.This transfer of energy by the movement of particles cause convection.

During the day the heat surface above the earth exposed to the sun's rays is heated. This rise in temperature,decreases the density of the air and the warm air rises.

This air cools down and becomes denser. This dense cool air sink back and forces the warm air to rise again.

This transfer of movement of particles causes convection. This cycle is the cause of winds and thus energy is transferred through the atmosphere.

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Lance Armstrong bikes at a constant speed up the Col d’Izoard, a famous mountain pass. Assume his teammates do such a good job r

svetoff [14.1K]

Work done against gravity to climb upwards is always stored in the form of gravitational potential energy

so we can say

$W = mgh$

here h = vertical height raised

so here we know that

$h = 14.1 sin7.3 km$

here we have

$h = 1.79 km$

now from above equation

$W = (83 kg)(9.81 m/s^2)(1.79 \times 10^3 m)$

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3 years ago

A uniform brick of length 21 m is placed over

Paha777 [63]

Answer:

15.75 m

Explanation:

First, let's look at the top brick by itself. In order for it not to tip over the bottom brick, its center of gravity must be right at the edge of the bottom brick. So the edge of the top brick must be 10.5 m from the edge of the bottom brick.

Now let's look at both bricks as a combined mass. We know the total length of this combined brick is 10.5 m + 21 m = 31.5 m. And we know that for it to not tip over the edge of the surface, its center of gravity must be at the edge. So the edge of the combined brick must be 31.5 m / 2 = 15.75 m from the edge of the surface.

6 0

4 years ago

4. A family leaves from New York City and is flying to Los Angles which is 2800mi away. It takes

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The average speed of the whole travel is equal to 400 mph.

Why?

From the statement, we know that whole travel is divided into three parts. For the first part (traveling from New York to Chicago), we have that it was 3.25 hours and the covered distance was half of the total distance (1400mi). For the second part, we have that it was 1 hour (layover time), and the covered no distance. For the third part (traveling from Chicago to Los Angeles), we have that it was 2.75 hours, and it took the other half of the total distance (1400mi).

We can calculate the average speed of the whol travel using the following formula:

$AverageSpeed=\frac{distance_{1}+distance_{2}+distance_{3}}{time_{1}+time{2}+time_{3}}$