John sees Hua running towards him at 11 m/s. While running, Hua throws a ball to John at 5 m/s. What is the speed of the ball as observed by John? A 5 m/s B 6 m/s CO 55 m/s DO 16 m/s

A car crosses an intersection as a fire engine approaches the intersection at 50 ft/s. how far does the fire engine travel while stopping, if the acceleration is −6t?   Round to two decimal places.

Our heroine is trapped in a rectangular room that is 10 feet by 16 feet, with a ceiling that is 9 feet above the floor. The room is filling with water at a rate of 60 cubic feet per minute. When the water reaches a depth of 5.5 feet, how fast is the water rising? (V = LWH)