As you ride upward in an elevator at a constant velocity, what two forces act on your body and what is the net force on you?

Gravitational force is the force that attracts any object with mass towards the center of the Earth. It is commonly referred to as weight when discussing everyday objects. The strength of this force can be calculated using the equation: \( F_g = m \times g \), where \( F_g \) is the gravitational force, \( m \) is the mass of the object, and \( g \) represents the acceleration due to gravity (approximately 9.8 m/s² on Earth). This force is always directed downward. When you are in an elevator, this is the force that makes you feel like you are being pulled towards the floor. It does not change whether you are standing still, accelerating, or moving at a constant velocity, being purely dependent on your mass.

The normal force is a supportive force provided by a surface that counteracts other forces. When you're in an elevator, the floor provides this support, pushing you upward. If you stand on a bathroom scale, it measures this normal force. At rest, or moving at a constant velocity, the normal force equals your weight (the gravitational force). So, its magnitude can again be found using \( F_n = m \times g \). It's called 'normal' because it acts perpendicular (normal) to the surface exerting it. If the elevator accelerates, this force changes: moving upward increases it, while moving downward decreases it. However, at constant velocity, it remains balanced with gravity.

Newton's First Law, also known as the law of inertia, states that an object will remain at rest, or in uniform motion in a straight line, unless acted upon by a net external force. This means that if you are riding in an elevator moving at a constant velocity, the net force acting on you must be zero. The forces thus balance each other out. More practically: the downward gravitational force is exactly counteracted by the upward normal force. This balance keeps you moving at the same speed without any noticeable jerk or shift, illustrating that the motion of objects continues unchanged without a net force.