In a steam engine, steam at 140°C in a turbine does work on an external system, and the steam leaves the turbine at 100°C. The efficiency of the steam engine is 5%. The relevant physical principle is a. the second law of thermodynamics
b. the first law of thermodynamics
c. operation of a heat pump
d. specific heat capacity

The diagrams show objects’ gravitational pull toward each other. which statement describes the relationship between diagram x and y? gravity attracts only larger objects toward one another. gravity attracts larger objects only if they are close to one another. if the masses of the objects increase, then the force between them also increases. if distance between the objects increases, then the amount of force also increases.

All motion is caused by force? true or false

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3