Answer:

Explanation:
14 lb force is required to stretch the spring by 4 inch distance
So we have



stretch in the spring is given as

now we will have



Now we need to find the work to stretch it by x = 10 in = 0.254 m
so we have



The y-component of the initial velocity vector is zero only in scenarios A and C. The weight/package on either plane inherits a non-zero x-component that matches the plane's horizontal velocity, but with respect to the vertical direction the objects are at rest, and dropping them from a given height doesn't confer them an initial vertical velocity. On the other hand, if the object was thrown upward and allowed to fall, or shot downward by a cannon, then the initial vertical velocity would be non-zero.
In scenario B, the dolphin must have some non-zero y-component of velocity in order to launch itself out of the water, because otherwise it would stay at a fixed depth.