# How to calculate velocity using Java

In this demo, we are going to learn how to calculate the final velocity of an object or a body in Java. We will be taking time, acceleration, displacement, and initial velocity as the parameters.

## Calculating the velocity in Java

**Formulae to calculate velocity:**

There are two general formulae to calculate velocity, v:

- v = u + a*t
- v^2 = u^2 + 2*a*s

where,

u is the initial velocity in m/s,

a is the acceleration in m/s^2,

s is the displacement in meters, and

t is the time taken in seconds.

**Steps to write the program:**

Step 1: Define variables u, a, s, and t of float data type to represent the parameters.

Step 2: Take the input of initial velocity and acceleration from the user.

Step 3: Ask the user if the third parameter used to calculate the velocity is time or displacement.

Step 4: Depending on the third parameter, use the appropriate formula to calculate the velocity, and store it in a variable v of float data type.

Step 5: Print the value of velocity stored in v.

**Java program to calculate velocity of an object:**

import java.util.Scanner; import java.lang.Math; public class velocity { public static void main(String[] args){ float v, u, a, s, t; String c; //Variable to store the choice of third parameter. /*Getting the values of u and a from the user*/ Scanner input = new Scanner(System.in); System.out.println("Enter the value of initial velocity: "); u = input.nextFloat(); System.out.println("Enter the value of acceleration: "); a = input.nextFloat(); /*Asking the user if the third parameter is time or displacement*/ System.out.println("Press 't' or 'T' to enter the value of time; press 's' or 'S' to enter the value of displacement:"); while(true) { c = input.next(); if((c.charAt(0) == 't' || c.charAt(0) == 'T') && c.length() == 1) { /*Since the user chose time, take the value of t and calculate velocity using the first formula*/ System.out.println("Enter the value of time: "); t = input.nextFloat(); v = u + a * t; break; } else if((c.charAt(0) == 's' || c.charAt(0) == 'S') && c.length() == 1){ /*Since the user chose displacement, take the value of s and calculate velocity using the second formula*/ System.out.println("Enter the value of displacement: "); s = input.nextFloat(); v = (float) Math.sqrt(u*u + 2*a*s); break; } else { /*This condition is entered when the user inputs an incorrect character */ System.out.println("Please enter the correct character."); } } System.out.println("Velocity = " + v); } }

**Output:**

Example 1) For, u = 0, a = 10, t = 5,

Enter the value of initial velocity: 0 Enter the value of acceleration: 10 Press 't' or 'T' to enter the value of time; press 's' or 'S' to enter the value of displacement: t Enter the value of time: 5 Velocity = 50.0

Example 2) For, u = 2.4, a = 5, s = 10,

Enter the value of initial velocity: 2.4 Enter the value of acceleration: 5 Press 't' or 'T' to enter the value of time; press 's' or 'S' to enter the value of displacement: s Enter the value of displacement: 10 Velocity = 10.283968

## Leave a Reply