A physics student stands on the edge of a cliff and throws a rock downward. It hits the ground with K Joules of kinetic energy. The student then throws another identical rock upward with the same initial speed, and then it hits the ground also. Neglecting air resistance, the second rock hits the ground with a kinetic energy of ____ J.
+37084 If there is no air friction.....when the rock comes down to its launch point it will be going the same speed as when it was launched, so it will be traveling downward at the same speed as the first rock was thrown (down) and will have the same energy at impact: #2 K joules
