Added GroundToGroundProjectileMotion (#6714)

* Added GroundToGroundProjectileMotion

* Fix checkstyle issues.

* Fix checkstyle issues.

src/main/java/com/thealgorithms/physics/GroundToGroundProjectileMotion.java

@@ -0,0 +1,90 @@
+package com.thealgorithms.physics;
+
+/**
+ * Ground to ground projectile motion calculator
+ *
+ * Ground to ground projectile motion is when a projectile's trajectory
+ * starts at the ground, reaches the apex, then falls back on the ground.
+ *
+ * @author [Yash Rajput](https://github.com/the-yash-rajput)
+ */
+public final class GroundToGroundProjectileMotion {
+
+    private GroundToGroundProjectileMotion() {
+        throw new AssertionError("No instances.");
+    }
+
+    /** Standard gravity constant (m/s^2) */
+    private static final double GRAVITY = 9.80665;
+
+    /**
+     * Convert degrees to radians
+     *
+     * @param degrees Angle in degrees
+     * @return Angle in radians
+     */
+    private static double degreesToRadians(double degrees) {
+        return degrees * (Math.PI / 180.0);
+    }
+
+    /**
+     * Calculate the time of flight
+     *
+     * @param initialVelocity The starting velocity of the projectile (m/s)
+     * @param angle The angle that the projectile is launched at in degrees
+     * @return The time that the projectile is in the air for (seconds)
+     */
+    public static double timeOfFlight(double initialVelocity, double angle) {
+        return timeOfFlight(initialVelocity, angle, GRAVITY);
+    }
+
+    /**
+     * Calculate the time of flight with custom gravity
+     *
+     * @param initialVelocity The starting velocity of the projectile (m/s)
+     * @param angle The angle that the projectile is launched at in degrees
+     * @param gravity The value used for the gravity constant (m/s^2)
+     * @return The time that the projectile is in the air for (seconds)
+     */
+    public static double timeOfFlight(double initialVelocity, double angle, double gravity) {
+        double viy = initialVelocity * Math.sin(degreesToRadians(angle));
+        return 2.0 * viy / gravity;
+    }
+
+    /**
+     * Calculate the horizontal distance that the projectile travels
+     *
+     * @param initialVelocity The starting velocity of the projectile (m/s)
+     * @param angle The angle that the projectile is launched at in degrees
+     * @param time The time that the projectile is in the air (seconds)
+     * @return Horizontal distance that the projectile travels (meters)
+     */
+    public static double horizontalRange(double initialVelocity, double angle, double time) {
+        double vix = initialVelocity * Math.cos(degreesToRadians(angle));
+        return vix * time;
+    }
+
+    /**
+     * Calculate the max height of the projectile
+     *
+     * @param initialVelocity The starting velocity of the projectile (m/s)
+     * @param angle The angle that the projectile is launched at in degrees
+     * @return The max height that the projectile reaches (meters)
+     */
+    public static double maxHeight(double initialVelocity, double angle) {
+        return maxHeight(initialVelocity, angle, GRAVITY);
+    }
+
+    /**
+     * Calculate the max height of the projectile with custom gravity
+     *
+     * @param initialVelocity The starting velocity of the projectile (m/s)
+     * @param angle The angle that the projectile is launched at in degrees
+     * @param gravity The value used for the gravity constant (m/s^2)
+     * @return The max height that the projectile reaches (meters)
+     */
+    public static double maxHeight(double initialVelocity, double angle, double gravity) {
+        double viy = initialVelocity * Math.sin(degreesToRadians(angle));
+        return Math.pow(viy, 2) / (2.0 * gravity);
+    }
+}