Force in science, especially for grade 8, is defined as a push or pull upon an object resulting from its interaction with another object. It can change the object's state of rest or motion, speed, direction, or shape

. Key points about force:

• It is a vector quantity, meaning it has both magnitude (size) and direction

• Force can cause an object at rest to move, stop a moving object, speed it up, slow it down, or change its direction

• The SI unit of force is the Newton (N), named after Sir Isaac Newton, and force is calculated as mass times acceleration (F = m × a)

• Forces occur in pairs, according to Newton's Third Law: for every action, there is an equal and opposite reaction

Types of force include:

• Contact forces, which require objects to touch (e.g., friction, muscular force)

• Non-contact forces, which act at a distance without direct contact (e.g., gravitational force, magnetic force, electrostatic force)

In summary, force is any push or pull that can cause an object to move, stop, change speed or direction, or alter its shape, and it is fundamental in understanding motion and interactions in physics at the grade 8 level.