The greenhouse effect is a warming effect caused by certain gases that retain heat from sunlight. Without such gases, the average surface temperature of the Earth would be below freezing, and as explained by the Encyclopedia of Environmental Science, “life, as we know it, would not exist.”
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The global warming debate is centered upon whether added greenhouse gases released by human activity will overheat the Earth and cause harmful effects.</span><span>
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Answer: The bond that hold water molecules together are due to shared electrons. The bond of shared electrons is known as a covalent bond.
Explanation: Water is held together by bonds known as covalent bonds, in which electrons are shared by the elements. In this case, the two hydrogen atoms and the one oxygen atom share a bond in which they share electrons, attaining a full outer shell.
Answer:
Explanation:
When a body is held against a vertical wall , to keep them in balanced position , normal force is applied on their surface . this force creates normal reaction which acts against the normal force and it is equal to the normal force as per newton's third law . Ultimately friction force is created which is proportional to normal force and it acts in vertically upward direction . It prevents the body from falling down .
Hence normal force = reaction force .
From second law also net force is zero , so if normal force is N and reaction force is R
R - N = mass x acceleration = mass x 0 = 0
R = N .
Ranking normal force from highest to smallest
150 N , 130 N , 120 N
B )
Frictional force is equal to the weight of the body because the body is held at rest .
Ranking of frictional force form largest to smallest
7 kg , 5 kg , 3 kg , 1 kg .
Here frictional force is irrespective of the normal force acting on the body because frictional force adjusts itself so that it becomes equal to weight in all cases here because it always balances the weight of the body .
