Magnets produce in the spaces surrounding them

After a car's engine has been running for a while, if you stand near the car's engine you can often feel heat coming from the engine as a result of a. radiation b. convection c. conduction

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?

Are formed where bumps from two surfaces come into contact ?