Answer this question fast please

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?

What was the first instrument to ever record an earthquake?

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?