What is how to find normal force?

The normal force is the force exerted by a surface on an object in contact with it. It's always perpendicular to the surface. Here's how to find it:

• Understanding the Concept: The <a href="https://www.wikiwhat.page/kavramlar/Normal%20Force">normal force</a> is a contact force that prevents an object from passing through a surface. It's a reaction force in accordance with Newton's Third Law.

• Free Body Diagram (FBD): Draw a <a href="https://www.wikiwhat.page/kavramlar/Free%20Body%20Diagram">free body diagram</a> of the object. Include all forces acting on the object, such as gravity (weight), applied forces, friction (if applicable), and, of course, the normal force.

• Identify Relevant Axis: The normal force is usually (but not always) along the y-axis (vertical). Choose an appropriate coordinate system.

• Apply Newton's Second Law: Apply <a href="https://www.wikiwhat.page/kavramlar/Newton's%20Second%20Law">Newton's Second Law</a> (ΣF = ma) along the axis perpendicular to the surface. This usually means ΣFy = may.

• Solve for Normal Force:

  • Horizontal Surface, No Other Vertical Forces: If the object is resting on a horizontal surface and there are no other vertical forces acting on it, the normal force (N) is equal to the weight (mg) of the object: N = mg.
  • Horizontal Surface, Additional Vertical Forces: If there's an applied force pushing down on the object (Fa_down), the normal force increases: N = mg + Fa_down. If there's an applied force pulling up on the object (Fa_up), the normal force decreases: N = mg - Fa_up. Make sure mg - Fa_up > 0, because otherwise the object would be accelerating upward and no longer in contact with the surface.
  • Inclined Plane: On an inclined plane, the normal force is equal to the component of the weight perpendicular to the plane. If the angle of inclination is θ, then N = mg * cos(θ).
  • Acceleration: If the object is accelerating vertically (ay ≠ 0), then ΣFy = may. For example, if the object is accelerating upward, N - mg = may, so N = mg + may.

• Units: The normal force is measured in <a href="https://www.wikiwhat.page/kavramlar/Newtons">Newtons</a> (N).