Two different bumper designs are shown here. view of the front of the car with bumper Design A (balloons) and bumper design B (metal bar) Recall that if the colliding objects have hard surfaces, the collision is elastic. Based on this description, which bumper design is more likely to result in an elastic collision? Predict how this bumper design will change the force that car 2 experiences during the collision.

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.