physics
posted by sam .
An automobile accelerates from rest at 1.3m/s^2 for 19s. The speed is then held constant for 23s, after which there is an acceleration of 0.9m/s^2 until the automobile stops.
What total distance was traveled?
Answer in units of km.

X1 = (1/2)a*19^2 = 234.7 m
Attained velocity:
Vmax = 1.3*19 = 24.7 m/s
X2 = 24.7 * 23 s = 568.1 m
X3 = (average speed)*(deceleration time)
= (Vmax/2)*(Vmax/a)= ___?
Add them up for total distance, and convert to km. 
here is another way:
make it to X1,X2,X3
X1=(1/2)(1.3*19)(19)
X2=(1.3*19)(23)
X3=(1.3*19)/(0.9)(1/2)(1.3*19)
total distance = X1+X2+X3