Calculating Velocity and Acceleration of a Truck in Motion

[Rylynn97]

A truck traveling east has a velocity of 26 m/s. (a) Calculate its velocity after accelerating at 1 m/s2. (b) The truck then decelerates at -2 m/s2 for 3 s. Now what is its velocity? (c) The truck then takes 8s to change its velocity to 21 m/s. What was its final acceleration?

I tried using 1s (a), and I got 27 m/s. Using 27 m/s in (b), I got 21 m/s. But then for (c) the velocity is also 21, so it doesn't make any sense. Help?

 

[lylos]

The process you followed is exactly right. I would guess that there's some typo in the problem. But for part C, if the truck was at 21 m/s then took 8s to get to 21 m/s. What would it's acceleration be?

 

[Rylynn97]

Ahh, I see. Thank you! ^___^

 

[willingtolearn]

just a little discussion, In part (a), how about the car accelerating at 3 m/s2, then the answer will be 29m/s2 ?

 

[learningphysics]

just a little discussion, In part (a), how about the car accelerating at 3 m/s2, then the answer will be 29m/s2 ?

In part a) is it accelerating for 1s ? doesn't say in the question, but I'm guessing it's supposed to be...

Yeah, then it would come out to: v = v0 + at = 26 + 3(1) = 29m/s The units are m/s not m/s^2.

 

[willingtolearn]

Thanks