1. A swimmer at the bottom of a pool 3 m deep looks up and sees a circle of light. If the index of refraction of the water in the pool is 1.33, find the radius of the circle.

2. As the speed of computer operations increases, computer architecture acquires greater importance; the time required to transfer a signal between the central processing unit (CPU) and memory can be a limiting factor in determining the time required for computation. What is the maximum separation between a memory chip and the CPU to allow transfer information between these units in less than 0.5 ns?

3. A swimmer at S in Figure develops a leg cramp while swimming near the shore of a calm lake and calls for help. A lifeguard at L hears the call. The lifeguard can run 9 m/s and swim 3 m/s. He knows physics and chooses a path that will take the least time to reach the swimmer. Which of the paths shown in Figure does hetake?

Transcribed Image Text:

Shore D. C. B. Sand Water %24