Fixes TheAlgorithms#9191: Add module for calculating energy-mass equivalenc

Author: Dhruv127

physics/einstein_mass_energy_equivalence.py

@@ -0,0 +1,35 @@
+# Einstein's Mass-Energy Equivalence
+# This code calculates the energy equivalent of a given mass using Einstein's mass-energy equivalence equation, E=mc².
+
+# Source: https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence
+
+def mass_energy_equivalence(mass: float, c: float = 299792458) -> float:
+    """
+    Calculate the energy equivalent of a given mass using Einstein's mass-energy equivalence equation, E=mc².
+
+    Args:
+        mass (float): Mass in kilograms.
+        c (float): Speed of light in meters per second (default value is the speed of light in a vacuum).
+
+    Returns:
+        float: Energy equivalent in joules.
+
+    Examples:
+        >>> mass_energy_equivalence(1)
+        8.987551787368176e+16
+        >>> mass_energy_equivalence(5, 3e8)
+        1.125937723421022e+18
+    """
+    if mass < 0:
+        raise ValueError("Mass cannot be negative")
+    if c <= 0:
+        raise ValueError("Speed of light must be positive")
+
+    energy = mass * c**2
+    return energy
+
+if __name__ == "__main__":
+    import doctest
+
+    # Run doctests
+    doctest.testmod()