1. Mar 17, 2013

### acelya

1. The problem statement, all variables and given/known data

A car, as shown in the figure, is going in a curvilinear road. The size of the car will be neglected.

2. Relevant equations

Its acceleration is a = 0.5*e^t m/s^2.

3. The attempt at a solution

If it goes 18 meters on its way, then calculate its velocity and acceleration.

I have one more question. A particle is making linear action. Its velocity in the origin is 4 m/s. If particle is slowing down with acceleration a = -3/2*v^1/2 m/s^2, calculate the elapse time and its taking way until it stops(v=0).

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2. Mar 17, 2013

### Staff: Mentor

I assume that is the tangential acceleration.

Given acceleration, how do you find velocity and distance?

3. Mar 17, 2013

### acelya

Yes, that is the tangential acceleration.

I don't know how can I find their values, bacause it is going on a curvilinear road and there is a p value (you can see in the figure) p=30m. I must use this value of p.

4. Mar 17, 2013

### Staff: Mentor

You'll use the radius to find the centripetal component of the acceleration.

But first things first. How can you find the velocity and distance, given the tangential acceleration? Hint: Calculus.

5. Mar 17, 2013

### acelya

I must use the integral. Distance velocity v=0.5e^t+c1 and distance x=0.5e^t+c1t+c2 (c1,c2 constant values). But then, it is going 18 meters on the road.

6. Mar 17, 2013

### Staff: Mentor

Good. What are c1 and c2? (Those depend on the initial conditions.)

7. Mar 17, 2013

### acelya

But I don't know where the car was on the road firstly. If at t=0, it was in origin, then c1=-0,5 , c2=0. But, this question don't tell us it was in the origin at first.

8. Mar 17, 2013

### Staff: Mentor

You have to know the initial velocity and position or be able to make reasonable assumptions. That it starts from rest and at x = 0 seems reasonable. How did you get c2 = 0?