The force exerted by a magnet on an object depends on various factors, including the strength of the magnetic field, the properties of the magnet and the object, and the distance between them. To calculate the force used to lift an object with a magnet, you can use the following equation:
F = (B x V x μ₀) / (2 x d)
Where: F is the force in Newtons (N) B is the magnetic field strength in Tesla (T) V is the volume of the object in cubic meters (m³) μ₀ is the permeability of free space, approximately 4π x 10^(-7) T*m/A d is the distance between the magnet and the object in meters (m)
This equation represents the simplified case of a uniformly magnetized object and assumes a simple cylindrical magnet and a ferromagnetic object. If the object is not uniformly magnetized or has a different shape, the calculation becomes more complex and may require additional considerations.
Note that the force calculated using this equation represents the maximum possible force of attraction between the magnet and the object. In real-world scenarios, factors such as surface conditions, angle of contact, and other forces (such as gravity) may affect the actual force required to lift the object.