two ice skaters, karen and david, face each other while at rest, and then push against each other's hands. the mass of david is three times that of karen. how do their speeds compare after they push off? karen's speed is the same as david's speed. karen's speed is one-fourth of david's speed. karen's speed is one-third of david's speed. karen's speed is four times david's speed. karen's speed is three times david's speed.