displacement
the change in position of an object
acceleration
the rate at which velocity changes over time;
an object accelerates if it speed, direction, or both change
kinetic energy
the energy of an object that is due to the object's motion
vector
a physical quantity that has both magnitude and a direction
scalar
a physical quantity that has magnitude but no direction
projectile motion
the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth
weight
a measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe
contact force
result from the physical interaction between objects
>applied force
>friction force
>tension force
>normal force
field force
doesn't have to be physical interaction
>gravitational force
>magnetic force
>electric force
Newton's 1st law of motion
an object in motion will stay in motion and an object at test will stay at rest unless acted on by a net external force
Newton's 2nd law of motion
the acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to the object's mass
Newton's 3rd law of motion
for every action there is an equal and opposite reaction
normal force
a force that acts on a surface in a direction perpendicular to the surface
gravitational force
the mutual force of attraction between particles of matter
equilibrium
the state in which the net force on an object is zero
work
the product of the component of a force along the direction of displacement and the magnitude of the displacement
work-kinetic energy theorem
the net work done by all the forces acting on an object is equal to the change in the object's kinetic energy
potential energy
the energy associated with an object because of the position, shape, or condition of the object
mechanical energy
the sum of kinetic energy and all forms of potential energy
power
a quantity that measures the rate at which work is done or energy is transformed
momentum
a quantity defined as the product of the mass and velocity of an object
impulse
the product of the force and the time over which the force acts on an object
impulse-momentum theorum
Ft=p
stopping times and distances
they two depended on the impulse-momentum theorum
conservation of momentum
momentum is conserved in collisions
momentum is conserved for objects pushing away from each other
perfectly inelastic collision
a collision in which two objects stick together after colliding
perfectly inelastic collisions can be analyzed in terms of momentum
KE is not conserved in inelastic collisions
elastic collision
the two objects bounce after the collision so that they move separately
KE is conserved in elastic collisions
inelastic collsion
the two objects deform during the collision
KE decreases
the objects move separately after the collision