Answer: Option (a) is the correct answer.
Explanation:
Resources which are created by human beings are known as man-made resources.
For example, glass, rayon, nylon etc are all man-made resources.
Whereas resources which are naturally created are known as natural resources.
For example, wind, air, water etc are all natural resources.
Thus, we can conclude that out of the given options time is not a natural resource.
Answer:
The coefficient of kinetic is

Explanation:
The forces in the axis 'x' and 'y' using law of Newton to find coefficient of kinetic friction
ΣF=m*a
ΣFy=W-N=0
ΣFy=Fn-Fu=m*a


Now to find the coefficient can find the acceleration using equation of uniform motion accelerated

So replacing the acceleration can fin the coefficient:
