Answer:
D, Im not very sure about this but I would say D
Explanation:
I tried
The compression curve would be theoretically given for a system of bodies in which the spring applies the force (Although in the same way the following process can be extrapolated to any system, depending on the type of Force to consider) For a spring mass system, the strength is given by Hooke's law as

Where,
K = Spring constant
x = Displacement
If we integrate based on distance we would have

This integral represents the area under the Force Curve based on each distance segment traveled.



This is the same formula that represents the elastic potential energy of a body. Therefore the correct answer is D.
Answer:
4v/3
Explanation:
Assume elastic collision by the law of momentum conservation:

where v is the original speed of car 1, v1 is the final speed of car 1 and v2 is final speed of car 2. m1 and m2 are masses of car 1 and car 2, respectively
Substitute 

Divide both side by
, then multiply by 6 we have



So the final speed of the second car is 4/3 of the first car original speed
Newton’s Law: F = MA
A = F/M (change equation)
12.6 N/ 2.4 kg = 5.25
Answer: acceleration is 5.25 m/s^2