2-9. A shock absorber consists of two equal-length springs which are “nested” together. It is designed to arrest the motion of a 20 kg mass that is dropped m above the top of the springs from an at-rest position, and the maximum compression of the springs is m. If follows a normal distribution and the outer spring has a stiffness N/m, determine the distribution of required stiffness of the inner spring.

Solution

Thus

Ans.

Ans.

Therefore, the required stiffness of the inner spring .