1. A 1.2 x 10^4 kg truck is travelling south at 22 m/s. a) What net force is required to bring the truck to a stop in 330 m? b) What is the cause of this net force? Answer: a) 8.0 x 10^3 N [N] 2. Each of the four wheels of a car pushes on the road with a force of 4.0 x 10^3 N [down]. The driving force on the car is 8.0 x 10^3 N [W]. The frictional resistance on the car is 6.0 x 10^3 N [E]. Calculate the following: a) the mass of the car b) the car's acceleration Answer: a) 1.6 x 10^3 kg b) 1.2 m/s^2 [W] I have the answers to these two questions, but I really need help on how to understand and do it. So far... 1. a) v = d/t t = d/v t = (0.33 km)/(22 m/s ) t = 0.015 s a = v/t a = (22 m/s )/(0.015 s) a = 1466.7 m/s^2 ?? <====== stopped here because this makes no sense..