7)Millie slides at the same speed as Pam and they collide at right angles and then slide off together on the frictionless ice. Pam's mass to Millie's is 4/3. What is the ratio of their final to initial speeds?

8)Newton had stopped his cart - mass 500 kg - just before a 30^o hill covered in ice. He was stuck from behind by a 1500 kg coach - of mass1500 kg - travelling at 20 m/s. The two vehicles stuck together and slid up the hill. How far up the slope did they go?