you place a large pebble in a slingshot, pull the elastic band back to your chin, and release it, launching the pebble horizontally at a speed of vv. you then repeat the exact same procedure (pulling the elastic band back the same distance) with a smaller pebble. the smaller pebble leaves the slingshot with a speed of 5v5v. how does the mass of the larger pebble compare to that of the smaller pebble?