Number 2- Liquids
Number 3- Cells
Do you have a picture then I could determine 1 millimeter
Explanation:
Let us assume that the mass of a pitched ball is 0.145 kg.
Initial velocity of the pitched ball, u = 47.5 m/s
Final speed of the ball, v = -51.5 m/s (in opposite direction)
We need to find the magnitude of the change in momentum of the ball and the impulse applied to it by the bat. The change in momentum of the ball is given by :

So, the magnitude of the change in momentum of the ball is 14.355 kg-m/s.
Let the the ball remains in contact with the bat for 2.00 ms. The impulse is given by :

Hence, this is the required solution.
An atom is probably less than 1 nano-meter in size
Answer:
(a) 
(b) 
Explanation:
(a) We use Newton's law of universal gravitation, in order to calculate the gravitational force between electron and proton:

Where G is the Cavendish gravitational constant,
and
are the masses of the electron and the proton respectively and r is the distance between them:

The minus sing indicates that the force is repulsive. Thus, its magnitude is:

(b) We use Coulomb's law, in order to calculate the electric force between electron and proton, here k is the Coulomb constant and e is the elementary charge:

Its magnitude is:
