How can the same material bend in one situation but break in another

Free runners jump long distances and land on the ground or a wall. how do they apply newton’s second law to lessen the force of impact?

Name the non metal condut electricity

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.