For a system that experiences no external force in translation at zero h, the kinetic energy after a given time interval Is A. zero B. the same as before C. half of the initial velocityIf a 10 - kg piece of copper falls 100 meters, how much energy might be produced? 3.81 kCal B. 32 BTU 2344.65 CalWhat average force is necessary to stop a .45 caliber bullet of mass 15 grams and speed of 300 - as is penetrates a block to a distance of 5 cm? (Hint: Principle of Work and Energy) A. 12.5 kN B. 13.5 kN C. 12.0 KN