Is there a bigger planet than the sun

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

Apossible explanation for a set of facts that can be tested by further investigation is called

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force