1the earth's crust is made up of plates that can move. which of the following topographic features could be directly formed by the movement of the earth's plates? i. midocean ridges ii. mountains iii. sand dunes iv. coral reefs a. i, ii, and iii only b. ii, iii, and iv only c. i and ii only d. ii and iii only

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?