Two students design an experiment to see if pushing or pulling is more effective. They set up a 10 foot course. The first student pushes a heavy book down the course and the other times how long it takes. The students then switch roles and the second student pulls the box back along the same course as the first student times. They repeat this 5 times. Describe the quality of the design of this experiment. A) This is a well designed experiment. B) This is not well designed because 10 feet is too long. C) This is not well designed because they should not switch roles. D) This is not well designed because they should repeat it 5 times.

Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. which of the following best describes how such a telephone is able to transmit and receive information? a. the cellular telephone transmits, receives, and encodes information using only sound waves. b. the cellular telephone transmits, receives, and encodes information using only electromagnetic waves. c. the cellular telephone transmits information by electromagnetic waves to a receiver which then encodes them and produces sound. d. the cellular telephone transmits information by sound waves to a receiver which then encodes them and produces electromagnetic waves.