A world-class tennis player can serve a tennis ball at 110 mi/h (about 49 m/s ). The length of a tennis court is 78 ft . Approximately how long does an opponent have to react from the instant the ball is served until the ball reaches the opponent?

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)