a push or pull on an object; needed to change an object's motion
force has both____________and _______________. (; between)
forces combined on the same object
have a net froce greater than zero and will change an object's motion
equal forces acting in opposite directions, have a net force equal to zero and will not change an object's motion
what type of force can change an object's motion?
can forces acting on different objects be added together?
the tendency of an object to resist change in its motion
amount of matter in an object
what does the amount of inertia an object have depend on?
Newton's first law of motion
which law is this?
an object at rest will remain at rest and an object moving at constant velocity will continue moving at constant velocity unless acted upon by an unbalanced force
the law of inertia
what is newton's first law of motion also known as?
the net force of an object is equal to the product of its acceleration and its mass
what is newton's second law of motion; F= MA
Newton (kg x meters per second per second)
what unit is used to measure force?
force that one surface exerts on another when they rub against each other; acts in a direction opposite to the direction an object is moving
the types of surfaces involved in how hard they push together
what does the strength of friction depends on
occurs when solid surfaces slide over each other
occurs on an object roles over surface
occurs when an object moves through a liquid or gas
what friction needs the most force to overcome?
the force that pulls objects towards each other
when the only force acting on an object is gravity, what is that called?
9.8 m/s squared
if an object is in freefall, how fast does it accelerate regardless of the mass?
any object that is thrown
objects falling through air experiences a type of fluid friction, which is called_______
the greatest velocity that the object reaches
the force of gravity, or a person or object at the surface of a planet
weight = mass × acceleration
what is the formula for weight?
The Newton because weight is the force of gravity
What is the unit of measurement for weight and why?
The force of gravity acts between objects in the universe
What does the law of universal gravitation state?
The mass of the objects and the distance between the objects
what does the strength of gravity depend on?
Newton's third law of motion
what is the law that states:
if one object exerts a force on another object, then the second object exerts a force of equal strength in opposite direction on the first object
the forces are acting on two different objects, they have to be acting upon the same object to be able to be added up
why can action and reaction forces not be added up?
the product of an objects mass and velocity
momentum = mass times velocity (P=MV)
what is the formula for momentum? (write out the word for the symbol: ex. plus for +)
Kilograms times meters per second per second
what is the unit of measurement for momentum? (write everything in words: ex. milliliters plus killoleters per millenium)
Same as its velocity
what direction this momentum facing?
The total momentum of the objects and an interaction is the same before and after the interaction
what is the law of conservation of momentum state?
Because the gases that expel the downward force exerts an equal but opposite force in an upward direction (in other words: a rocket pushes gas DOWN at the same speed they need to be going UP, because of the 3rd law, it shoves them into the air)
why can a rocket rise into the air?
the upward pushing force is
the thrust must be_________ than the downward pull
any object that travels around another object in space
the force that causes an object to move in a circle; means" center seeking"