Question

You are driving your car, and the traffic light ahead turns red. You apply the brakes for 2.13 s, and the velocity of the car decreases to +4.90 m/s. The car's deceleration has a magnitude of 3.55 m/s2 during this time. What is the car's displacement?

Answer 1

if the initial velocity was v,

v - 3.55*2.13 = 4.90
v = 12.46 m/s

the displacement s is thus

s = 12.46*2.13 - 3.55/2 * 2.13^2
s = 18.49 m