Physics Ch 3 Flashcards
Independence of motion
horizontal and vertical components of 2D motion are independent of each other
Vector
quantities with both magnitude and direction
Head to tail method
graphical way to add vectors
tail
starting point of the vector
head (tip)
final, pointed end of the arrow
Resultant vector
vector sum of 2+ vectors
magnitude of the resultant
length as measured by a ruler
Direction of the resultant
measure the angle it makes with the reference frame using a protractor
Commutative
characteristic of vector addition in that vectors can be added in any order and you’d still get the same result
Multiply vector by positive scalar
magnitude changes, direction stays the same
Multiply vector by negative scalar
magnitude changes, new vector in opposite direction
Component
piece of a vector that points in either the vertical or the horizontal direction; every 2-d vector can be expressed as a sum of 2 vertical and horizontal vector ______(s)
Analytical methods
vector addition and subtraction employs geometry and simple trigonometry rather than the ruler and protractor of graphical methods
Projectile motion
motion of an object thrown or projected into the air, subject to only the acceleration of gravity
Projectile
object that is thrown
Trajectory
path a thrown object travels
Air resistance
in two-dimensional projectile motion, this is negligible
Range
horizontal distance R traveled by a projectile
Velocity
object has this relative to a medium; medium has this relative to an observer on solid ground
Relative velocities
velocity relative to some reference frame
Relativity
study of how different observers moving relative to each other measure the same phenomenon
Classical relativity
limited to situations where speeds are less than about 1% of the speed of light (less than 3000 km/s)
