Need help this engineering dynamics

please make your step by step clear it helps to understand

Review Part A The boy jumps off the flat car at A with a velocity of v = 4 ft/s relative to the car as shown. He lands on the second flat car B. Each car has a weight of 74 1b . The Determine the speed of car A. boy D's weight is 60 1b. Both cars are originally at rest. Neglect the mass of the carOs wheels. (Figure 1) Express your answer to three significant figures and include the appropriate units. HA ? ft VA= 1.499 S Submit Previous Answers Request Answer Figure 1 of 1 ( > X Incorrect; Try Again; 5 attempts remaining Part B e = 4 ft/s 13 Determine the speed of car B. B Express your answer to three significant figures and include the appropriate units. LA UB= Value Units