I'm stuck on this question. In order to find the spring constant the equation that I constructed does not take into account the accelerating elevator(f=kx). How am I supposed to think of an equation that takes into account the accelstation of the elevator.

1 1 [10 points] 12 d M + m Figure 1: (a) A- box of mass M is attached at the end of a spring that is hung from the ceiling of an elevator. When the elevator is accelerating upward with acceleration a, the spring stretched by a distance yo from the unstretched position (Fig. 1, left). Find the spring constant k in terms of M, g, a and yo. Now, you place the same box and spring horizontally and shoot a bullet with mass m and velocity v to the box (Fig. 1, right). The bullet gets embedded to the box and they move together after the collision. Let's measure the speed v of the bullet. (b) If the velocity of the box plus the bullet is ' right after the collision, find the speed v' in terms of m, M and v. (c) The box and the bullet stop after the spring has stretched a distance d. Find v in terms of M, m, g, a, d and yo. U O 99+