Help Please! Four identical springs are attached to a stopper as shown. In the uncompressed case and cases 1-3, a force is applied to compress to the spring and hold it at rest. The given spring lengths and applied forces are shown. Determine the spring force, spring constant and stretch length in each case. Note: Drawing is not to scale.

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.