A physics student stands on the rim of the canyon and drops a rock. The student measures the time for it to reach the bottom to be 3.2 seconds. How deep is the canyon?

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.

Conductionhope this .

Because there is no air in the jar, the vibrations can not travel through the air and create sound.  (that's why there is no sound in space, there is no air)