Compute all parts of given problem:
Problem: A rock climber stands on top of a 60 m high cliff hanger a pool of water. He throws two stones vertically downward 1.0 s apart and observes that they cause a single splash. The initial speed of the first stone was 1.8 m/s.
Part A: How long after the release of the first stone does the second stone hit the water?
Part B: What was the initial speed of the second stone?
Part C: What is the speed of the first stone as it hits the water?
Part D: What is the speed of the second stone as it hits the water?
Please show all work and clearly explain.