FORCES

• Forces can be classified as contact forces or Action-at-A-Distance forces.
• A force is any push or pull that changes the motion, shape or position of an object.
• Contact forces are exerted by objects that touch one another, while action-at-a-distance forces act at a distance without physical contact between the two bodies involved.
• Contact forces are exerted by one body on another when they touch.
• Examples of contact forces include friction, applied force, normal force, air resistance, tension, and spring force.
• Resultant Force = Vector Sum of all the Forces acting on an Object
• Friction is a resistive force that opposes motion when two surfaces rub against each other.
• Action-at-a-distance forces act at a distance without touching.
• Force = Mass x Acceleration
• Friction is a type of contact force that opposes relative movement between two surfaces.
• Contact Forces are forces between two objects when they touch each other.
• Action-at-a-distance Forces are forces between two objects without touching each other.
• Force is a push or a pull with an SI unit of newtons (N).
• Force is a vector quantity.
• Vector quantities are quantities with both magnitude (measurement) and direction.
• The direction of a vector quantity may be specified in terms of the vector’s orientation on the x-y plane, where the x-axis is along the horizontal and the y-axis is along the vertical.
• The direction of a vector quantity may also be specified in terms of cardinal directions North, South, East, and West.
• Force can make an object move.
• Force can stop an object from moving.
• Force can change an object’s shape or direction of the object’s motion.
• The total or sum of forces exerted on an object is known as the summation of forces.
• The object will move or change the direction of its motion on the direction of the summation of forces acting or exerted on it.
• Types of Forces: Contact Force and Action-at-a-Distance Force
• Important Contact Forces: Normal force, Applied force, Tension, Spring force, Air resistance, Friction
• Types of Friction: Static friction, Sliding friction, Fluid friction and Rolling friction
• Contact Force are types of forces that act when two objects interact

  with each other through direct physical contact.
• Action-at-a-distance forces interactions between two interacting objects that

  are not in direct contact with each other but can employ

  a push or pull despite distance.
• Normal force - The force exerted from the surface where an body lies or rests.
• Normal force is is perpendicular with the surface.
• Applied force is an interaction of one object by a person or another object to accelerate, change velocity, or change the direction of another object
• Tension are forces that are directed toward ropes, cables, and strings
• The spring force occurs when a spring compresses or extends.
• The direction of the spring force is always contrary to the direction of the displacement or size of deformation
• Spring force follows Hooke's Law: F=-kx
• Air Resistance is the type of force the air exerts on a moving object
• Air resistance is opposite to the movement of a falling object
• Air resistance is stronger for objects with high speed and larger surface area
• a force of friction acts when two objects are sliding against one another
• Friction's force is parallel to the surface
• Friction is always opposite to the direction of motion