Answer to Question #326842 in Physics for Rachel

Question

A car changes its velocity from 20 m/s [N] to 20 m/s[S] in 5.5 s. If the mass of the car is 1500 kg, 

what is the net force acting on it?

Answer 1

The Newton's second law says

$$F=ma=\frac{m\Delta v}{\Delta t}$$ $$F=\frac{1500*(20-(-20))}{5.5}=10909\:\rm N$$

The force is directed toward South.