Subatomic particles cannot be broken down any further
We will define the Total mass to calculate the force, so our values are:
Total Mass 
The Weight is,

Through the hook's Law we calculate X.
, where x is the lenght of compression and K the Spring constant.
We don't have a K-Spring, but we can assume a random value (or simply let the equation in function of K)

I assume a value of 

Answer:
The cart mark (a) has the most potential energy and the cart marked (b) has the most kinetic energy
Answer:
B. 14
Explanation:
For an element:
- Atomic number: is the number of protons in the nucleus (p)
- Mass number: it is the number of protons (p) + neutrons (n) in the nucleus
For Al (aluminium), we have:
p = 13
p + n = 27
Substituting the first equation into the second one, we find the number of neutrons:
n = 27 - p = 27 - 13 = 14
Answer:
speed and velocity, c would be my guess