If an arrow is shot upward on the moon with a velocity of 55 m/s, its height after t seconds is given by h = 55t - 0.04t2 . Find the (instantaneous) velocity over at t = 10 sec.

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?