Motion
Newtonian mechanics are a little outdated, so why do we still use it for studying motion?
It's not too complex and works for most objects.
What is acceleration?
A change in velocity per unit of time and occurs when speed, direction, or both change.
Ex: Doubling force will double acceleration.
What is force and how is it measured?
A push or pull on an object. It's measured by the SI unit, the Newton.
What is a balanced & unbalanced forces?
BALANCED: Multiple, simultaneous forces whose pushes and pulls cancel each other out resulting in a zero net force.
UNBALANCED: Where multiple, simultaneous forces act on an object and one force is stronger creating a change in motion called acceleration.
What is friction?
A contact force working against the movement of objects as they touch, moving past each other.
What is distance?
How far a moving object has traveled to get from one point to another.
What is circular motion?
movement along a circular path
What is a scalar and vector?
SCALAR: measures magnitude
VECTOR: measures magnitude and direction
What is speed?
A measure/scalar of how quickly an object has traveled.
What are the three types of friction?
Static - friction between two objects that are not yet in motion relative to each other.
Sliding - friction between two objects when they are moving relative to each other...like sliding or pushing something. Less frictions than static and makes movement easier.
Rolling - friction between two objects moving against each other using wheels or casters. Less friction than static or sliding therefore, easier to move objects.
What is displacement?
A change in position. The distance traveled from only the starting point to the ending point, including direction.
What is centripetal acceleration?
Acceleration toward the center of a circular path.
What is a contact force?
A force created from one object touching another
Ex: friction
What is Newton's First Law of inertia?
An object at rest stays at rest, an object in motion stays in motion unless acted on by a net external force. expressed as F=ma
What are the four fundamental forces? Which is the strongest, which is the weakest?
strong nuclear force, weak nuclear force, electromagnetic force, gravitational force
The strong nuclear force is the strongest, gravitational force is the weakest.
What is momentum?
Momentum of a moving object is equal to its velocity multiplied by its mass.
What is free fall?
The motion of objects that fall due to gravity alone with no other forces acting on them.
What is a field force?
A force between objects at a distance - they don't have to be touching
Ex: gravity, electromagnetism
What is Newton's Second Law of acceleration?
The acceleration of an object is directly proportional to the net force acting on the object and is inversely proportional to its mass.
What is inertia?
An object continues in its current state of rest or movement unless acted on by an external force. Mass is a measure of inertia.
What is frame of reference and what are some examples used in math and science?
The point from which something is observed. Number lines, coordinate planes, diagrams or pictures.
Example question: Sitting still, it appears to me that I'm not moving. From what frame of reference would I appear to be moving? (from the moon)
What is projectile motion?
The two-dimensional motion of any flying object such as kicking or throwing a ball.
What is normal force?
Where two objects make contact...they are both acting on each other.
What is Newton's third law of action-reaction?
For every action force, there is an equal and opposite reaction force.
What is velocity?
A change in position per unit of time.
Ex: mph (miles per hour), =m/s (meters per second)