The coefficient of static friction between the flat bed of the truck and the crate it carries is 0.32. Determine the minimum stopping distance s which the truck can have from a speed of 64 km/h with constant deceleration if the crate is not to slip forward.

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.