Change 200km/hr into m/sec

In what direction does the medium move relative to the direction of the wave? explain.

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

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?