Java :

import java.util.Scanner;

public class Main{

	public static void main(String[] args) {
		// TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
double v0=5.5;
double v1=50.9;
double t=4.5;
double a1=Math.round((v1-v0)*10000/t);
double a=a1/10000;
System.out.printf("The average acceleration is "+a);
	}

}