A 1300-kg car initially has a velocity of 22.2 m/s due south. It brakes to a stop over a 180 m distance. (a) What is the magnitude of the car’s acceleration, in

Question

find the magnitude of the car

Answer 1

Use the kinematic relation

 

v_f² - v_i² = 2ad ⇒

 

a = (v_f² - v_i²)/(2d) = [(0)² - (22.2)²]/[2(180)] m/s² = -1.369 m/s²

 

The minus sign means the acceleration is opposite the direction of motion.