Final answer:
To determine the gravitational force on Earth's surface, the expression F = m * g is used, where 'm' is mass and 'g' is the acceleration due to gravity.
Step-by-step explanation:
The expression that can be used to determine the magnitude of the gravitational force you feel while on the surface of the Earth is F = m * g. Here, 'F' represents the force of gravity or the weight of an object, 'm' is the mass of the object, and 'g' is the acceleration due to gravity, which is approximately 9.81 m/s² on Earth's surface. This simplification arises from Newton's law of universal gravitation, which in its full form is F = G * (m1 * m2) / r², where 'G' is the universal gravitational constant, 'm1' and 'm2' are the masses of the two objects, and 'r' is the distance between the centers of the two masses. For objects on the Earth's surface, 'm2' and 'r' are constants (Earth's mass and radius), so the force can be simplified to the weight equation F = m * g.