# Finding future x position with changing velocity

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1. Feb 13, 2016

### heartshapedbox

1. The problem statement, all variables and given/known data
At what time in the future will the x-component of the masses position be at 0m?

2. Relevant equations
x=x,initial+(integral0,t)(v,xcomponent)(dt)

3. The attempt at a solution
The solution is 3.1 seconds... not really sure where to start :(

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2. Feb 13, 2016

### Ray Vickson

In order to carry out the calculation indicated in your equation above, you need to know the x-component of v at time t---which you can (and should) write as v_x(t), or vx(t), using the "x2"" button on the gray palette at the top of the input panel. You are given an expression for acceleration, and you are given enough information to work out the initial vx(0) and vy(0) values, so you can work out vx(t) and vy(t). After that you can just go ahead and carry out the work in your equation.

3. Feb 13, 2016

### heartshapedbox

Thank you!!!! i know how to get the initial x and y components at t=0. What equations should I be using to get the position 0 at the unknown time

4. Feb 13, 2016

### Ray Vickson

Well, YOU were the one that wrote down the necessary equation.

5. Feb 14, 2016

### heartshapedbox

Yeah! I am unsure of how to use it.

6. Feb 15, 2016

### haruspex

As Ray indicated in post #2 you first need another integral equation, one relating velocity to acceleration.