Physics, Kinematics
posted by Jackie on .
You drive with a constant speed of 15.1 m/s for 23.4 s. You then accelerate for 28.7 s to a speed of 25.8 m/s. You then slow to a stop in 37.1 s. How far have you traveled?
I've tried dividing this into 3 parts.
1st constant speed
15.1m/s*23.4s=353.34 m
2ndaccelerating
I solved for acceleration, v=v0+at, a=0.0836 m/s^2, then plugged into x=x0+v0t+(1/2)at^2 where x=0+(23.4m/s)(28.7s)+(1/2)(.0836m/s^2)(28.7)^2=706.35
353.34+706.35=1059.35
I'm stuck after this. What do I do with the negative acceleration for the last part? I appreciate any guidance.

ok on first leg.
Second leg, accelerating;
distance= average velocity*time
= 1/2 (15.1+28.7)*25.8
third leg:
distance= avg velocity*time
= 1/2 (28.7+0)*37.1 
That isn't correct. Any other thoughts on this problem?

Nevermind, you just accidentally switched the velocity and time. It's (1/2)(15.1+25.8)*(28.7) and (1/2)(25.8)*37.1. Thank you so much for your help! I can't believe I didn't see that before.