Calculating Velocity and Position of a Car Over Time Using Equations

[thaaampie]

A car starts at rest, and at time t=0 accelerates at a constant rate of 2 ft/sec^2 for 10 seconds. Then the car decelerates at a constant rate of -1 ft/sec^2 until it stops.

Write the equations for the velocity and the position for time t, where o<=t<=10.

Write the equations for the velocity and the position for time t, where t=> 10.

When did the car stop, and how far did it go?

 

[Nex Vortex]

If you would show your attempt at the problem then I will be able to help you with it. However, without anything more then the problem, it is impossible to tell what you are having problems with.

 

[thaaampie]

That's the problem, I'm not exactly sure how to set up the equations for the problem. Word problems are not my forte.

 

[Nex Vortex]

The formulas you will need are the following:
$$x=v_1+\frac{1}{2}at^2$$
$$v_2=v_1+at$$

The initial velocity and accelerations are given, therefore that should answer your first two questions after plugging everything in.

In order to solve the last question, you must first determine the car's velocity after the first 10 s (using the second equation listed above). Then you can use that velocity to find the time required to stop (using the same equation).

If you need some more help with this problem, don't hesitate to post back.