A vector quantity that tends to produce an acceleration of a body in the direction of its application or a change of the direction that the object is moving or a deformation of a body
Vectors are usually drawn as arrows.
Contact and Non-Contact forces
Instantaneous and Constant forces
The weight of an object is the force of attraction that gravity exerts on it.
Depends on: mass and gravity
w = m x g
4.1 WEIGHT AND MASS
MASS is an invariable quantity that depends on the amount of matter.
Mass is measured with a balance.
WEIGHT depends on gravity. So, it changes with it.
Weight is measured with a dynamometer.
9.8 newtons = 1 kilopond
4.3 WEIGHT AND DENSITY
d = m/v
w = V x d x g
upthrust = V x d x g
5.1 ARCHYMEDES' PRINCIPLE
Law of buoyancy
Archimedes' principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.
Boats and submarine
6 FORCES &
6.1 NEWTON'S LAWS
6.1.1 First Law
An object in motion on which no forces act has uniform rectilinear motion.
6.1.2 Second Law
A constant force exerted on an object gives it a constan acceleration that is directly proportional to the force and inversely proportional to the object's mass.
6.1.3 Third Law
When one body exerts a force on a second body, the second body
simultaneously exerts a force equal in magnitude and opposite in
direction on the first body.
6.2 FORCES &
An object is in equilibrium when the resultant of all the forces that act on it is nil.
6.3 FORCE &
Work is done when an object is displaced because a force acts on it, either partialy or completely in the same direction as the motion.
W = F x d
6.3.1 Unit of
Joule: is the work done by an object that, subjected to a force of 1 N, is displaced 1 m in the same direction as the force.
7 ENERGY &
Objects have mechanical energy when they move at a certain speed or are displaced with respect to their position of equilibrium, or are at a certain height above the ground.
EK is the energy that an object in motion has. it is depend on the mass of the object and how fast it moves (its speed)
An object stores potential energy when it moves in the opposite direction to a force acting on it.