Answer to Question #305443 in Physics for Cris

Question

A motorist traveling with a constant speed of 20.0 m/s passes a school-crossing corner, where the speed limit is 15.0 m/s. Just as the motorist passes, a police officer on a motorcycle at the corner starts off in pursuit with constant acceleration of 5.0 m/s^2. What is the total distance traveled by the motorist

Answer 1

$$d_M=v_0t=20t$$

$$d_C=at^2/2=2.5t^2$$

$$d_M=d_C$$

$$20t=2.5t^2$$

$$t=8\:\rm s$$

The total distance traveled by the motorist

$$d_M=20*8=160\:\rm m$$