Force in Physics is found as the product of Mass Times Acceleration. The Acceleration of a falling object due to Earth's Gravity has been established as 9.8 meters per second every second or 9.8 m/s2.
Write 2.00 kilograms × 9.8 m/s2 or 19.6 (kg•m/s2).
The unit of (kg•m/s2) or "kilogram-dot-meters-per-second-squared" is known as the "Newton" so the force sought is equal to 19.6 Newtons.