Question

A rock is dropped into a water well and it travels approximately 16t2 in t seconds. If the splash is heard 3.5 seconds later and the speed of sound is 1087 feet/second, what is the height of the well?

Answer 1

T1 + T2 = 3.5 : T1 time for the rock to reach bottom of well and T2 time for the sound to reach the top of the well. 16 * T12 = 1087 * T2 : same distance which the height of the well. T2 = 3.5 - T1 : solve for T2 16 * T12 = 1087 * (3.5 - T1) T1 = 3.34 seconds Height = 16 * (3.34)2 = 178 feet (to the nearest unit)

Answer 2

T1 + T2 = 3.5 : T1 time for the rock to reach bottom of well and T2 time for the sound to reach the top of the well. 16 * T12 = 1087 * T2 : same distance which the height of the well. T2 = 3.5 - T1 : solve for T2 16 * T12 = 1087 * (3.5 - T1) T1 = 3.34 seconds Height = 16 * (3.34)2 = 178 feet (to the nearest unit)