On a cold winter day, a penny (mass 2.50 g) and a nickel (mass 5.00 g) are lying on the smooth (frictionless) surface of a frozen lake. with your finger, you flick the penny toward the nickel with a speed of 2.25 m/s . the coins collide elastically; calculate both their final speeds. what are the directions of their final velocities, opposite or the same?

Which type of reaction is shown in this energy diagram? energy products activation energy reactants time o a. endothermic, because energy is released to the surroundings o b. exothermic, because energy is absorbed from the surroundings o c. exothermic, because energy is released to the surroundings o d. endothermic, because energy is absorbed from the surroundings