A 2.50 kg beverage can is thrown directly downward from a height of 4m with an initial speed of 3m/s. the air drag on the can is negligible. What is the kinetic energy of the can as it reaches the ground at the end of its fall and when it is halfway to the ground? The kinetic energy of the can and the gravitational potential energy of the can-earth system 0.200s before the can reaches the ground? for the latter take the reference point y=0to be at the ground.