A 1500kg car traveling at 100km/h south collides with a 1200 kg car traveling north at 100km/h. The heavier car continues to move south after the collision, but slows to 25.0km/h. How fast is the lighter car moving after the collision? Please help!!

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)