I don’t know the answer

Help me please

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

The air that we breath is made mostly of which gaseous molecule

Select for each of the following statements whether it is correct or incorrect. (a) in an isothermal expansion of an ideal gas. (b) the temperature remains constant. (b) the pressure remains constant. (c) there is work done by the gas. (d) there is heat added to the gas. (e) the change in internal energy equals zero.