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3 years ago

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

Physics

1 answer:

shtirl [24]3 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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Which method determines the relative age of Earth's sedimentary layers based on their organization?

MrRa [10]

Answer:

Relative age-dating involves comparing a rock layer or rock structure with other near-by layers or structures. Using the principles of superposition and cross-cutting relationships, and structures such as unconformities, one can determine the order of geological events.

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3 years ago

Why the effect of gravitational force is more in liquid than in solid?

LekaFEV [45]

Gravitational force depends only on mass and distance, not on the state of matter.
The forces of attraction between molecules in matter are electromagnetic in nature, not gravitational.
These attractive forces are stronger in a solid than in a liquid than in a gas.
Gravitational forces between molecules is completely negligible compared to the em forces.

So, key answer is inter-molecular forces of solids is stronger than liquids.

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3 years ago

Read 2 more answers

George created an advertisement for a retail store that sold clothes. He added a discount in the form of a coupon that the custo

likoan [24]

Answer:

The advertisement feature that George can use is a coupon booklet with the local newspaper for delivery

Explanation:

George focus on promotion rather than using the other stores strategy of word-of-mouth. Different types of promotion: advertising, public relations, direct selling and sales promotions.A temporary reduction in the price, such as 50% off. Reduction amount may be a percentage that can be marked on the package.A coupon booklet is inserted into the local newspaper for delivery. Also on checkout the customer can be given a coupon based on products purchased. The consumer is automatically entered into the contest/event by purchasing the product.

Displays:-

A board on which messages are written in crayon.

Consumers get one sample for free, after their trial and then could decide whether to buy or not

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3 years ago

Block A has a mass of 0.5kg, and block B has a mass of 2kg. Block is is released at a height of 0.75 meters above B. The coeffic

VikaD [51]

Answer:

0.075 m

Explanation:

The picture of the problem is missing: find it in attachment.

At first, block A is released at a distance of

h = 0.75 m

above block B. According to the law of conservation of energy, its initial potential energy is converted into kinetic energy, so we can write:

$m_Agh=\frac{1}{2}m_Av_A^2$

where

$g=9.8 m/s^2$ is the acceleration due to gravity

$m_A=0.5 kg$ is the mass of the block

$v_A$ is the speed of the block A just before touching block B

Solving for the speed,

$v_A=\sqrt{2gh}=\sqrt{2(9.8)(0.75)}=3.83 m/s$

Then, block A collides with block B. The coefficient of restitution in the collision is given by:

$e=\frac{v'_B-v'_A}{v_A-v_B}$

where:

e = 0.7 is the coefficient of restitution in this case

$v_B'$ is the final velocity of block B

$v_A'$ is the final velocity of block A

$v_A=3.83 m/s$

$v_B=0$ is the initial velocity of block B

Solving,

$v_B'-v_A'=e(v_A-v_B)=0.7(3.83)=2.68 m/s$

Re-arranging it,

$v_A'=v_B'-2.68$ (1)

Also, the total momentum must be conserved, so we can write:

$m_A v_A + m_B v_B = m_A v'_A + m_B v'_B$

where

$m_B=2 kg$

And substituting (1) and all the other values,

$m_A v_A = m_A (v_B'-2.68) + m_B v_B'\\v_B' = \frac{m_A v_A +2.68 m_A}{m_A + m_B}=1.30 m/s$

This is the velocity of block B after the collision. Then, its kinetic energy is converted into elastic potential energy of the spring when it comes to rest, according to

$\frac{1}{2}m_B v_B'^2 = \frac{1}{2}kx^2$