Chapter 3 study guide

relationshiop between force, mass, and acceleration

acceleration depends on force and mass. the more applied force, the greater the acceleration.

Newton's second law

acceleration of an object is in the same direction of the net force.

equation for net force

Newtons=kg*m/s^2 (direction)

Friction

force that opposes the sliding motion of two surfaces that are touching.

factors affecting friction

-the type of surface
-the force pressing them together

causes of friction

microwelds- welding or sticking that occurs when the bumps of two objects occur.

types of friction (4)

Fluid friction, static friction, sliding friction, rolling friction

air resistance

causes objects to fall with different accelerations and speed

terminal velocity

the highest speed an object can reach, depends on the size, shape, and mass of the object

gravity

an attractive force between any two objects

factors that affect gravity

mass of the objects, distance between the objects

long-range force

rapidly decreases with increased distance gravity is never 0

free fall

falling objects which are acted on only by gravity

acceleration of gravity

On Earth is 9.8m/s^2 (down)
given the symbol (g)

equation for calculating weight

weight(n)=mass(kg)*acceleration of gravity(m/s^2)

differences in mass and weight

weight changes with location, mass is constant

weightlessness

not feel the effects of gravity

projectile motion

anything that is thrown or shot through the air

path of projectile

gravity causes projectiles to follow around a parabolic path

centripetal force

acceleration towards the center of a curved or circular path

Newton's third law

when one object on another, the second object exerts a force on the first one that is equal in size and opposite in direction

action-reaction pairs

every force in nature is accompanied by a reaction force.

Rocket propulsion

the engines in the rocket push hot gas out the back

momentum

property of all moving objects

equation for calculating momentum

p=mass*velocity

conservation of momentum

momentum doesn't change unless mass or velocity change, momentum can be transferred from one object to another

what happens when objects collide

when two objects of equal mass collide at the same time, they have equal momentum after a collision. If the objects have different masses, the momentum will not be equal but will be conserved.