Newton's First Law
What puts things in motion?
An unbalanced force
How does an increase in mass affect acceleration?
For a constant force, an increase in the mass will result in a decrease in the acceleration
an action force exerts a force on another object and a reaction force exerts an equal and opposite force back on the object
What is friction?
the force that two surfaces exert on each other when they rub against each other
when forces are balanced on an object what happens?
The object will either stay at rest or continue in constant acceleration.
What is Newton's first Law?
Things at rest stay at rest (unless acted on by an unbalanced force), and objects in motion stay in motion (unless acted on by an unbalanced force.)
What is Newton's second Law?
a net force acting on an object produces an acceleration that is directly proportional to the net force and inversely proportional to the mass
What is Newton's third Law?
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first
what is static friction?
Force of friction present where there is no relative motion
when forces acting upon an object are unbalanced what happens?
the object acceleration will change, meaning the object will either speed up, slow down or change directions.
What is an unbalanced force?
When the forces acting on an object are not equal and the motion of the object changes
What is the eqation used in Newton's 2nd Law?
F=ma
The acceleration of an object depends on what two things?
The size of the force applied, and the mass of the object
What are three properties that can influence the amount of friction?
Surface area, amount of pressure, and surface texture or roughness
if something is moving at constant acceleration, are the objects fores balanced or unbalanced?
Balanced
What is inertia?
The tendency of an object to resist changes in motion
What factors determine the air resistance force on an object?
The air resistance force an object experiences depends on the object's speed and area
Why don't action and reaction forces cancel each other out?
because action and reaction forces act on different objects
What is a substance that is used to reduce friction called?
A lubricant
if you throw a tennis ball, are the forces acting on the tennis ball balanced or unbalanced?
unbalanced
Do all objects have inertia?
yes
What is the difference between mass and weight?
Mass is the amount of matter in an object. While weight is the force due to gravity that acts on an object's mass.
if two objects interact and create an action and a reaction force, but the two objects have different masses, are the action and reaction forces still equal?
yes!, regardless of mass or weight the action and reaction forces will always be equal.
without friction would a moving object ever stop?
only if the object collided or was stopped by another object, but the cause of stopping would not be friction.
True or false: when an object is moving that means that the forces on the object are unbalanced.
false!