Grade 9 Flashcards
Normal reaction force
The force that acts between objects and the surface they are in contact with. This force is always perpendicular (normal) to the surface.
Friction
This is the force that opposes motion.
Drag
The resistance due to pushing molecules aside. It is often related to velocity and keeps increasing until the object is no longer accelerating.
Tension
The force exerted by a string or cable.
Force
A vector quantity, a push or pull acting in a specific direction. Unit: N (Newtons)
Newton’s First Law
An object continue moving with a constant velocity unless upon an unbalanced force.
Newton’s Second Law
F= ma
Forces equals mass times acceleration. The bigger the m/a the bigger the force.
Newton’s Third Law
For every action there’s an equal and opposite reaction.
Scalar
A measurement without direction (ex. temperature, speed, distance, time)
Vector
A measurement with a direction (ex. velocity, force, displacement)
Distance
An actual path line, may be curved (meters)
Displacement
Path line (direct, shortest) in a certain direction (meters)
Speed
Rate of change of distance in respect to time (meters per second)
Velocity
Rate of change of displacement in respect to time (meters per second + direction)
Acceleration
Rate of change of velocity in respect to time (meters per second squared)
