please help me with the following physics questions. im completely stuck and would really appreciate your help in advance, please. thank you

001 (part 1 of 2) 2.0 points A 2050 kg car moving east at 10.4 m/ s collides with a 3280 kg car moving east. The cars stick together and move east as a unit after the collision at a velocity of 5.78 m / s. a) What is the velocity of the 3280 kg car before the collision? Answer in units of m / s. 002 (part 2 of 2) 2.0 points 13) What is the decrease in kinetic energy during the collision? Answer in units of J. 003 2.0 points Two ice skaters approach each other at right angles. Skater A has a mass of 27.8 kg and travels in the +3: direction at 2.7 m / s. Skater B has a mass of 86.6 kg and is moving in the +3; direction at 1.31 m/s. They collide and cling together. Find the nal speed of the couple. Answer in units of m / s. 005 (part 1 of 2) 2.0 points A simple Utube that is open at both ends is partially lled with a liquid of density 651 kg/mg. Water is then poured into one arm of the tube, forming a column 12 cm in height, as shown in the diagram. 006 (part 2 of 2) 2.0 points A simple Utube that is open at both ends is partially lled with heavy liquid. A liquid of density 651 kg / In3 is then poured into one arm of the tube, forming a column 12 cm in height, as shown. light liquid 651 kg / n13 heavy liquid 1000 kg /m3 What is the difference in the heights of the two liquid surfaces? Answer in units of cm. light liquid 651 kg / n13 heavy liquid 1000 kg /m3 What is the difference in the heights of the two liquid surfaces? The density of heavy liquid is 1000 kg/mS. Answer in units of cm