A Red Cross helicopter delivers crates of medicine to a war-torn area because of the hilly terrain, the helicopter cannot safely land. Instead, the helicopter must hover above the ground, while someone drops the crates. The crates are designed to withstand "impact velocities" of up to 8.0 m/s.
a) Suppose the crates are dropped from rest, find the highest the helicopter can be off the ground, such that the crates don't break when they land?
b) The helicopter pilot accidentally starts ascending before the last crate is dropped. As a result, the last crate is "dropped" when the copter is 9.0 m off the ground and rising at 3.0 m/s. Compute how much time passes between when the crate gets dropped and when it lands?
c) Determine how fast is the crate from moving right before it hits the ground?