Science 8 - Q1 Forces

• Force - push or pull that causes change in the motion of an object. Required to initiate or terminate motion.
• Magnitude - refers to how strong the force is. Expressed in unit N, Dyn, LBS. (Greater Magnitude = Faster Velocity)
• Direction - refers to the point where the object goes.
• Point of Application - refers to the location where the force is applied.
• Line of Action - straight line passing through the point of application and is parallel to the direction of the force.
• Contact Force - is present when two or more surfaces or media touch and interact. Ex. Friction, Normal Force, Tension Force & Applied Force
• Friction Force - refers to the force that acts opposite or against another object.
• Normal Force - the force that acts perpendicular to an object. Supports an object as surface resist compression.
• Tension Force - the force applied and exerted to a string, rope, chain, cable and likes on an object.
• Applied Force - refers to the force exerted by a person or an object towards another person or object.
• Non-Contact Force - is constantly present in nature and does not need human intervention to arise.

  Ex. Gravitational Force & Magnetic Force
• Gravitational Force - the force that attracts objects towards earth.
• Magnetic Force - the force that is exerted on what we call a field of attraction or repulsion.
• Balanced Forces - are those which are of opposite directions and equal in magnitude.
• Unbalanced Forces - are those which are in the opposite direction and unequal in magnitude.
• Net Force - also called resultant force is the sum of all the forces that act on an object. Formula: Fnet = ΣF | Fnet = Fa + Fb
• Net Force = 0 (Balanced) no movement or change in velocity
• Net Force > 0 (Unbalanced) there is movement or change in velocity
• Motion - caused by unbalanced forces.
• Speed - length of distance traveled in a certain amount of time.
• Displacement - gap between the initial position and final position of an object.
• Velocity - speed at which something moves in one direction.
• Acceleration - rate of change of velocity of an object.
• Gravity - force of attraction between two objects with mass.
• Air Resistance - frictional force acting on an object moving through air or another fluid.
• Weight - measure of gravitational pull on an object due to its mass.
• Mass - amount of matter in an object.