Answer:
Rolling friction is much smaller than sliding friction because Rolling friction is considerably less than sliding friction as there is no work done against the body that is rolling by the force of friction. For a body to start rolling a small amount of friction is required at the point where it rests on the other surface, else it would slide instead of roll.
Rolling Friction example: Anything with weels (cars,skateboards) or a ball rooling.
Sliding Friction example: Bicycle brakes,skinning your knee walking,writing.
Hot air rises<span> because when you </span>heat air<span> (or any other gas for that matter), it expands. When the </span>air<span> expands, it becomes less dense than the </span>air<span>around it. The less dense </span>hot air<span> then floats in the more dense cold </span>air<span> much like wood floats on water because wood is less dense than water.</span>
Since the diameter of helium atom is approximately 
, therefore the diameter of helium atom in nano meter,
Answer:
Nucleus And electron cloud
Explanation:
Hope this helps
To solve this problem we will apply the concepts related to Ohm's law and Electric Power. By Ohm's law we know that resistance is equivalent to,
Here,
V = Voltage
I = Current
While the power is equivalent to the product between the current and the voltage, thus solving for the current we have,
Applying Ohm's law
Therefore the equivalent resistance of the light string is 
