8. A 50 kg figure skater moving West at 18 m's and collides with a 90 kg hockey player moving East at 12 m/s. They collide perfectly elastically - determine their final velocities. 9. A quarter tonne bike runs a red light doing 180 km/h [N]. A 10 tonne delivery truck is making a turn at 36 km/h [NE] when the bike collided into it. If they become stuck together then determine their final velocity and heat loss. Physics Incorporated 10. A 20 kg curling rock was tampered with and some TNT was placed in its center providing 4 184 J per g. The rock is initially moving forward at 5 m's and then the TNT detonates splitting the rock into 3 pieces. An 10 kg pieces flies forward at 100 m's and a 6 kg piece flies right at 150 m/'s. Find the velocity of the 3rd piece and the amount of TNT used to cause this ridiculous sabotage