[FEAT] Add general purpose Projectile Motion algorithm (Physics) (#6928)

[FEAT] Add general purpose Projectile Motion algorithm

Co-authored-by: Priyanshu1303d <priyanshu130d@gmail.com>
Co-authored-by: Deniz Altunkapan <deniz.altunkapan@outlook.com>

src/test/java/com/thealgorithms/physics/ProjectileMotionTest.java

@@ -0,0 +1,69 @@
+package com.thealgorithms.physics;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test class for the general-purpose ProjectileMotion calculator.
+ *
+ */
+final class ProjectileMotionTest {
+
+    private static final double DELTA = 1e-4; // Tolerance for comparing double values
+
+    @Test
+    @DisplayName("Test ground-to-ground launch (initial height is zero)")
+    void testGroundToGroundLaunch() {
+        ProjectileMotion.Result result = ProjectileMotion.calculateTrajectory(50, 30, 0);
+        assertEquals(5.0986, result.getTimeOfFlight(), DELTA);
+        assertEquals(220.7750, result.getHorizontalRange(), DELTA);
+        assertEquals(31.8661, result.getMaxHeight(), DELTA);
+    }
+
+    @Test
+    @DisplayName("Test launch from an elevated position")
+    void testElevatedLaunch() {
+        ProjectileMotion.Result result = ProjectileMotion.calculateTrajectory(30, 45, 100);
+        assertEquals(7.1705, result.getTimeOfFlight(), DELTA);
+        assertEquals(152.1091, result.getHorizontalRange(), DELTA);
+        assertEquals(122.9436, result.getMaxHeight(), DELTA); // Final corrected value
+    }
+
+    @Test
+    @DisplayName("Test launch straight up (90 degrees)")
+    void testVerticalLaunch() {
+        ProjectileMotion.Result result = ProjectileMotion.calculateTrajectory(40, 90, 20);
+        assertEquals(8.6303, result.getTimeOfFlight(), DELTA);
+        assertEquals(0.0, result.getHorizontalRange(), DELTA);
+        assertEquals(101.5773, result.getMaxHeight(), DELTA);
+    }
+
+    @Test
+    @DisplayName("Test horizontal launch from a height (0 degrees)")
+    void testHorizontalLaunch() {
+        ProjectileMotion.Result result = ProjectileMotion.calculateTrajectory(25, 0, 80);
+        assertEquals(4.0392, result.getTimeOfFlight(), DELTA);
+        assertEquals(100.9809, result.getHorizontalRange(), DELTA);
+        assertEquals(80.0, result.getMaxHeight(), DELTA);
+    }
+
+    @Test
+    @DisplayName("Test downward launch from a height (negative angle)")
+    void testDownwardLaunchFromHeight() {
+        ProjectileMotion.Result result = ProjectileMotion.calculateTrajectory(20, -30, 100);
+        assertEquals(3.6100, result.getTimeOfFlight(), DELTA);
+        assertEquals(62.5268, result.getHorizontalRange(), DELTA);
+        assertEquals(100.0, result.getMaxHeight(), DELTA);
+    }
+
+    @Test
+    @DisplayName("Test invalid arguments throw an exception")
+    void testInvalidInputs() {
+        assertThrows(IllegalArgumentException.class, () -> ProjectileMotion.calculateTrajectory(-10, 45, 100));
+        assertThrows(IllegalArgumentException.class, () -> ProjectileMotion.calculateTrajectory(10, 45, -100));
+        assertThrows(IllegalArgumentException.class, () -> ProjectileMotion.calculateTrajectory(10, 45, 100, 0));
+    }
+}