# I need some help with my c++ code

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main()
{
cout << "Enter the total time: ";
double t;
cin >> t;

cout << "Enter the step-size: ";
double step;
cin >> step;

double steps = ceil(t/step);

const double a = 9.806; // accel. due to gravity // m/(sec^2)

for (int count = 0; count <= steps; count++) {

double v = (a*t); // calculation for velocity

const double half = 0.5;
double x = (half)*(a)*(pow(t, 2)); // calculation for distance

cout << "t: " << setprecision(4) << fixed << t << "\tx: " << x << "\tv: " << v << endl;

t -= step;
}

return 0;

This is the result i'm getting:

Enter the total time: 0.1
Enter the step-size: 0.01
t: 0.1000 x: 0.0490 v: 0.9806
t: 0.0900 x: 0.0397 v: 0.8825
t: 0.0800 x: 0.0314 v: 0.7845
t: 0.0700 x: 0.0240 v: 0.6864
t: 0.0600 x: 0.0177 v: 0.5884
t: 0.0500 x: 0.0123 v: 0.4903
t: 0.0400 x: 0.0078 v: 0.3922
t: 0.0300 x: 0.0044 v: 0.2942
t: 0.0200 x: 0.0020 v: 0.1961
t: 0.0100 x: 0.0005 v: 0.0981
t: 0.0000 x: 0.0000 v: 0.0000

___________________________________

What I am trying to do is to begin from zero and work my way down to 0.1000.
I still need to enter 0.1 for the total time (which is variable "t" in the code).

How would I code it in order to make it begin from zero?

## Answers and Replies

chiro
Science Advisor
Hey physics=world.

You are setting your t as what you input. Instead what you should do is use another variable (say tstep), set it equal to zero and then instead of using t -= step you use tstep += step.

Take a look at your code again to see what's happening.

Hey physics=world.

You are setting your t as what you input. Instead what you should do is use another variable (say tstep), set it equal to zero and then instead of using t -= step you use tstep += step.

Take a look at your code again to see what's happening.

Are you saying get rid of my input "t"?

Are you saying get rid of my input "t"?

I see what your talking about. The "t" in both equation is not suppose to be the value taken from the user.
Thanks for helping me! :)