Radioactive isotopes are used to a. determine the absolute age of rocks. c. determine how rocks are formed. b. determine the relative age of rocks. d. determine how rocks are changed. select the best answer from the choices provided a b c d

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?