Quantities that have only magnitude. Eg. kg and mL
The property of a body to resist changes to its state of motion.
All the planets revolve around the sun
Push or pull
Terminal speed
The speed at which the acceleration of a falling object is zero because friction balances the weight.
Vector Quantities (give two examples)
Quantities that have both magnitude and direction. Eg. velocity and acceleration
Weight and mass
Weight: The force of gravity on an object.
Mass: Quantity of matter in an object. Mass is NOT volume!
Aristotle's natural motion
Thought to be straight up or straight down. Objects seek their natural resting place.
Net Force
The combination of all forces acting on an object is called the net force. 0 N does not always mean at rest!
Terminal velocity
Terminal speed together with the direction
Horizontal and vertical components of motion
Newton's first law
(Also known as the Law of Inertia) An object in motion will continue in its state of motion unless acted on by an outside force.
Aristotle's violent motion
Imposed motion. Result of forces that pushed or pulled (external cause).
Support Force
The upward or normal force
Lift
The whirling blades of a helicopter force air particles downward. The air forces the blades upward (Action and Reaction Forces). This upward reaction is called lift.
Resultant
The effect of what the two vectors are doing together. It is ALWAYS longer than the original vectors.
Newton's Second Law
Acceleration is directly proportional to force, and inversely proportional to mass.
When did Galileo believe a force is needed to keep an object moving?
Only when friction is present
Tension
Stretching force
What is needed for acceleration
A force external to the system. Action and reaction forces do not cancel each other when either of the forces is EXTERNAL TO THE SYSTEM being considered.
Projectile
Any object that moves through the air or space acted on only by gravity.
Newton's Third Law
For every force, there is an equal and opposite force.
What did Galileo believe were the properties of acceleration of an object?
A ball rolling down an inclined plane speeds up.
A ball rolling up an inclined plane - in a direction opposed to gravity - slows down.
A ball rolling on a smooth horizontal distance plane has almost constant velocity.
What does force cause?
acceleration
What increases and decreases pressure?
For a constant force, an increase in the area of contact will result in a decrease in the pressure.