The normal force on top of a loop refers to the force exerted by the surface of the loop on an object resting on top of it. It is always perpendicular to the surface of the loop and acts to prevent the object from falling through the loop.
The normal force on top of a loop can be calculated using the formula N = mg + mv^2/r, where N is the normal force, m is the mass of the object, g is the acceleration due to gravity, v is the velocity of the object, and r is the radius of the loop.
The normal force on top of a loop is affected by the mass of the object, the velocity and acceleration of the object, and the radius of the loop. These factors influence the magnitude of the normal force and can also affect its direction.
The normal force on top of a loop is important because it helps to keep an object in circular motion as it moves around the loop. Without the normal force, the object would simply fall through the loop due to the force of gravity.
As an object moves around a loop, the normal force changes depending on the position of the object on the loop. At the top of the loop, the normal force is at its maximum since the object is moving with the greatest velocity. As the object moves down the loop, the normal force decreases until it reaches its minimum at the bottom of the loop, where the velocity is zero.