There is no single, precise definition for strength, but we can characterize it as a Vector greatness (has module, direction and direction) capable of generating changes in the movement of a body and that is associated with actions such as pulling, pushing, moving etc.
Below are described situations in which forces act:
Force and Movement:In a constant velocity movement, called a uniform rectilinear movement, the net force on the moving body is zero. Therefore, we can understand that force is not related to speed itself, but rather to its variation. If there is speed variation (acceleration), there is force acting. This is the reasoning behind the Newton's first law (inertia).
Types of Force: When there is direct contact between two bodies, the forces involved are called contact forces. If the interaction between the bodies occurs at a distance, the forces involved are called field forces.
Example:
Pushing a car → Contact force
Gravitational attraction between the Sun and Earth → Field strength
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Strength and Balance: If the sum of all forces acting on a body is equal to zero, we say that that body is in equilibrium. For a bridge to remain balanced, dozens of forces are being exerted, and the sum total between them is nil.
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Force measurement unit:THE Newton's second law shows that the resulting force acting on a body is the result of the multiplication of the body's mass by the acceleration acquired by it, that is:
FR = m.a
How mass is used in kg and acceleration in m/s2, the force unit should be Kg.m/s². However, the unit for this magnitude in the International System of Units is the newton (N).
1N = 1 kg.m/s2
a newton is the force needed to accelerate to 1 m/s2 an object with a mass of 1 kg.
Dynamometer:O dynamometer is a measuring instrument that relies on the deformation of springs to determine the strength of a force. The image below shows a small dynamometer that measures the intensity of force needed to deform its elastic structure.
By Joab Silas
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
JUNIOR, Joab Silas da Silva. "What is strength?"; Brazil School. Available in: https://brasilescola.uol.com.br/o-que-e/fisica/o-que-e-forca.htm. Accessed on June 27, 2021.
