SCIENCE (Show your solution)

Part 1B A delivery truck hits a parked car from behind. The mass of the car is 2, 550 kg. What force is exerted on the car if (a) the car is rigid and accelerates to 4.5 m/s in 0.20 s? (b) the car has crumple zones and accelerates to 4.5 m/s in 0.30 s? 1. Rigid car 2. Car with crumple zones Given: Given: m = 2550 kg m = 2550 kg V, = 0m/s = 0m/s f = 4.5 m/s Uf = 4.5 m/s t = 0.20 s s t = 0. 30 s s F =? F =? (Show your solution.) Part 1C An engine receives 3850 J of heat and discards 2250 J to the atmosphere. 1. How much work is done by the engine? 2. What is its thermal efficiency? (Show your solution.)