diff --git a/algebra/sum_of_first_n_primes/sum_of_first_n_primes.java b/algebra/sum_of_first_n_primes/sum_of_first_n_primes.java
new file mode 100644
index 000000000..ccacaa9ca
--- /dev/null
+++ b/algebra/sum_of_first_n_primes/sum_of_first_n_primes.java
@@ -0,0 +1,40 @@
+// Returns the sum of the fist N prime numbers as inputted by user.
+// You can convert it into a method as well by
+
+import java.util.Scanner;
+import java.util.stream.IntStream;
+
+public class sum_of_first_n_primes {
+
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+        int n = Integer.parseInt(scan.nextLine());
+        int counter = 0;
+        int primeDividend = 2;
+
+        int[] numList = new int[n];
+        while (counter != n) {
+
+            boolean prime = true;
+
+            for (int i = 2; i <= Math.sqrt(primeDividend); i++) {
+
+                if (primeDividend % i == 0) {
+                    prime = false;
+                    break;
+                }
+
+            }
+
+            if (prime) {
+                numList[counter] = primeDividend;
+                counter++;
+            }
+            primeDividend++;
+        }
+
+        System.out.println("Sum of the first " + n + " primes " + IntStream.of(numList).sum());
+
+    }
+
+}
diff --git a/discrete/ackermann_peter/java/ackermann_peter.java b/discrete/ackermann_peter/java/ackermann_peter.java
new file mode 100644
index 000000000..9c594c6b1
--- /dev/null
+++ b/discrete/ackermann_peter/java/ackermann_peter.java
@@ -0,0 +1,23 @@
+// A java implementation of the Ackermann function using explicit recursion.
+
+
+public class ackermann_peter {
+
+	private static double M;
+	private static double N;
+
+	public static void main(String[] args) {
+		if (args.length != 0)
+			M = Double.parseDouble(args[0]);
+		if ((args.length > 1))
+			N = Double.parseDouble(args[1]);
+		System.out.println(ackermanCalculator(M, N));
+	}
+
+	public static double ackermanCalculator(double m, double n){
+		if (m == 0) return n +1;
+		if (m == 0) return ackermanCalculator(m -1, 1);
+		return ackermanCalculator(m-1, ackermanCalculator(m, n-1));
+	}
+
+}
diff --git a/physics/acceleration_formula/java/AccelerationCalculator.java b/physics/acceleration_formula/java/AccelerationCalculator.java
index 6d65ac57c..cfdef576e 100644
--- a/physics/acceleration_formula/java/AccelerationCalculator.java
+++ b/physics/acceleration_formula/java/AccelerationCalculator.java
@@ -10,7 +10,21 @@ public class AccelerationCalculator {
 	 * @param t - Time taken in seconds
 	 * @return acceleration in meter/second^2
 	 */
-	public static double calculateFor(double u, double v, double t) {
+	public static double calculateAcceleration(double u, double v, double t) {
 		return (v - u) / t;
 	}
+
+	/**
+	 *
+	 * @param u - Initial Velocity in meter/second
+	 * @param v - Final Velocity in meter/second
+	 * @param s - Displacement in meters
+	 * @return Acceleration in meter/second ^ 2
+	 */
+
+	public static double calculateAcceleration(double u, double v, float s) {
+		return ((Math.pow(u, 2) - Math.pow(v, 2)) / (2 * s)); // Derived from the u^2 = v^2 + 2ad formula.
+	}
+
+
 }
\ No newline at end of file