Normal force is the force exerted by a surface on an object that is in contact with it. It is always perpendicular to the surface and acts to prevent the object from going through the surface.
Finding the normal force is important for understanding the forces acting on the crates and ensuring that they are being moved safely and efficiently. It also helps in determining the amount of force needed to move the crates and in calculating the work done.
The normal force can be calculated by multiplying the mass of the object by the acceleration due to gravity (9.8 m/s^2) and the cosine of the angle between the object and the surface it is resting on. The equation is:
FN = mg cosθ
where FN is the normal force, m is the mass of the object, g is the acceleration due to gravity, and θ is the angle between the object and the surface.
The normal force can be affected by the weight and mass of the crates, the angle of the surface they are resting on, and the presence of any other external forces acting on the crates. Friction between the crates and the surface can also impact the normal force.
Yes, the normal force can be greater than the weight of an object if the surface is inclined or if there are other external forces acting on the object. In this case, the normal force is used to balance out the other forces and prevent the object from moving or accelerating.