(a) if th = 1100 k and tc = 400 k, what is the thermal efficiency?

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

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?

In general what determines whether atoms will form chemical bonds?