Ceramic is the most brittle of the materials you have specified.
Explanation:
average speed is the total distance divided by total time
A cell is made up of molecules and molecule is made up of atoms. So, they both need molecules to be made.
Answer:
Rest and motion are the relative terms because they depend on the observer's frame of reference. So if two different observers are not at rest with respect to each other, then they too get different results when they observe the motion or rest of a body.
Explanation With Example:
Imagine you are sitting inside a moving bus. When you look outside you will observe that you are moving. ... With respect to the roof of bus, you are at rest. Hence it is concluded that rest and motion are relative terms.