# Problem with distance in relation to acceleration.

BeeGeeks
Homework Statement
A 1200 kg car is at a red light on a horizontal road. When the road turns to green, (t0) he starts accelerating and reaches 14 m/s in 7 seconds. He then continues at a constant speed for 10 seconds, then brakes with a -3.5 m/s^2 acceleration.

All accelerations are assumed to be constant.

a) Calculate the amount of time he spends decelerating. (What I found through graphing : 4 seconds)

b) Graph the speed in relation to time starting with t0. (Done successfully)

c) Calculate the average speed in both the acceleration and deceleration phase. (7 m/s)<- this seems weird to me)

d) Calculate the total distance between the start of the acceleration until the final stop.

I'm having trouble with point d).

The problem

I don't understand how we can calculate a distance while the object is under acceleration. I can't wrap my head around it. Is there an equation I don't know about? Or am I overcomplicating things and it's just ( for this problem) an additional 2 meters per second during the acceleration phase, then 10 seconds of adding 14 m per second and then decreasing the number you add to your total by 3 every second starting by 14 during your deceleration? is it that obvious?

## Answers and Replies

Mentor
I don't understand how we can calculate a distance while the object is under acceleration.
Why not? It's moving isn't it? What's the average speed during each segment of the motion? Use that to find the distance traveled.

BeeGeeks
Why not? It's moving isn't it? What's the average speed during each segment of the motion? Use that to find the distance traveled.

Thanks!