A boy stands at the base of a building and throws a rock vertically upward (+y direction) with an initial speed of v0 = 24.0 m/s. How long after the rock is initially thrown will a person 15.0 m above him see the rock for the first time?

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.