What is an apparent change in the frequency of sound or light waves known as?

At what point the certain object feels zero garvitational force between earth and the moon. take the required information from the book. required: distance away from earth or moon

Astudent is working in the lab to determine how time affect impulse the student keeps the force the same in each row but changes impact the time some data is shown witch trial has the greatest a student is working in the lab to determine how time affect impulse the student keeps the fours the same in each row but change is the impact time some data shown witch trial has the greatest impulse

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.