# Car coasts to a stop: find acceleration, distance, average speed

1. Sep 13, 2016

### xxcrn

• Homework posted in wrong forum, so no template
Its my first time ever being in Physics and I need help with this probably really simple problem.

It first says, a car is initially traveling at 25m/s and then coasts to a stop in 12 seconds. What is its acceleration? **I took 25/12 and got 2.08 m/s. Hopefully that part is right?

Then it asks how far did it travel while slowing down? **This I didn't even know how to start.

The third part to this question is what was the average speed of the car when it was coasting. And I think for this you take the answer from the question above and divide it by 12.

Any help would be great!!

2. Sep 13, 2016

### Staff: Mentor

Firstly, you should use the homework section on PF here in which automatically a template will be inserted that guides you through the questions that always will have to follow. It's called relevant equations and is necessary to understand where to start with explanations. So:
What formulas do you have at hand, which deal with distance, velocity, acceleration and time?
Secondly, where did you get stuck? Have you made any efforts, beside dividing $25$ by $12$?

Which leads me to my next question: What is the result of $25 \frac{m}{s}$ divided by $12s$?
How is an average velocity / speed defined?

3. Sep 13, 2016

### xxcrn

Sorry its my first time one here. I have v=x/t, d=vt+ 1/2at(2)
I think I figured it out now, thanks anyway!