Lesson 14: Summary on The Concept of Force
- Dynamics is a branch of mechanics focused on the motion of objects and the forces that cause these movements.
- In this field, force is defined as an external agent capable of changing the state of rest or motion of an object.
- The concept of inertia describes an object’s resistance to changes in its state of motion.
- When multiple forces act on an object, their vector sum is called the net force. Acceleration refers to the rate at which an object’s velocity changes over time, either through changes in speed or direction.
- A system in dynamics is a collection of objects working together for a common purpose, with anything outside this system considered its surroundings.
- The principle of action and reaction, also known as Newton’s third law, states that forces between two objects are equal in magnitude and opposite in direction.
- Weight is the gravitational pull on an object, calculated as the product of its mass and the acceleration due to gravity.
- Normal forces are perpendicular forces exerted by surfaces in contact with each other, preventing objects from merging into one another.
- Force can cause various effects on an object, such as changing its state of rest or motion, altering its direction, or modifying its shape and size.
- Examples of contact forces include frictional force, tension force, and muscle power.
- Non-contact forces, or field forces, like gravitational force, electrostatic force, and magnetic force, act over a distance without direct physical contact.
- The fundamental forces in nature, in decreasing order of strength, include the strong nuclear force, electromagnetic force, weak nuclear force, and gravitational force.
- The strong nuclear force binds subatomic particles in the nucleus, while the weak nuclear force plays a crucial role in radioactive decay and nuclear reactions.
- Balanced forces acting on an object result in no net force and no change in motion, whereas
- unbalanced forces cause a change in velocity and/or direction of the object.
- The SI unit of force is the Newton (N), and its dimensional formula is [MLT−2][M L T^{-2}][MLT−2].
- One Newton is defined as the force needed to accelerate a 1 kg mass by 1 m/s².