Electrical energy.................
Answer: Moon is much smaller in size and has very less mass, when compared to our mighty earth and there is absence of strong magnetic field on the moon which could protect from the incoming solar radiation from the sun. Since there is no magnetic field, it can swipe off any materials that are present there on the moon, diminishing the atmosphere.
This is the reason why moon does not have any atmosphere.
Answer:
Explanation:
The force of kinetic friction on the block is defined as:
Where 
is the coefficient of kinetic friction between the block and the surface and N is the normal force, which is always perpendicular to the surface that the object contacts. So, according to the free body diagram of the block, we have:
Replacing this in the first equation and solving for :
I'm not sure of the numbers sense I dont have a calculator right now. The formula is 1/2*M*V^2.
