Give an example of forces adding together

Where is the potential energy throughout the loading, cocking, and releasing of the trebuchet?

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above