# I need some help with my c++ code

• C/C++
• physics=world
In summary, the program takes in a total time and step size from the user, calculates the number of steps needed, and then uses a for loop to calculate and output the acceleration, distance, and velocity at each step. However, there is an issue with the input for the total time, which is supposed to start from zero and work its way down to the user-input value, but instead, the user-input value is being used in the calculations. To fix this, a new variable should be used for the total time and the for loop should be adjusted accordingly.

#### physics=world

#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?

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.

chiro said:
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"?

physics=world said:
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! :)

It seems like you are trying to create a loop that starts from 0 and counts up to a certain value. To do this, you can replace the "for" loop in your code with a "while" loop. Here is an example of how you could modify your code to start from 0 and count up to 0.1:

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

int main()
{
double t = 0; // initialize t to 0
cout << "Enter the total time: ";
double end_time;
cin >> end_time;

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

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

while (t <= end_time) { // loop until t reaches the end_time
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; // increment t by the step size
}
return 0;
}

I hope this helps! Please let me know if you have any further questions or need clarification.

## What is C++ code?

C++ is a computer programming language commonly used for creating high-performance applications, operating systems, games, and more. It is an extension of the C programming language and is known for its speed, efficiency, and flexibility.

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