# Exam 1 Flashcards

displacement

the straight-line distance in a specific direction from starting (initial) position to ending (final) position

distance traveled

a measure of the length of the path followed by the object whos motion is being described, from initial to final position

- takes into account direction of travel
- total distance traveled

motion

the action or process of change in position

speed

rate of motion

velocity

rate of motion in a specific direction

average speed

distance traveled/time

instantaneous speed

the speed of an object at a specific instant of time

true or false

if the motion of the object under analysis is in a straight line and rectilinear, with no change in direction, average speed and average velocity will be identical in magnitude

instantaneous velocity

the velocity of an object at an instant in time

If your direction of motion changes your ________ changes

velocity (velocity changes as direction changes)

acceleration

the rate of change in velocity

when an object speeds up, slows down, starts, stops, or changes direction, it is _____

accelerating

average acceleration

the change in velocity divided by the time it took for the velocity change to take place

true or false: the direction of motion does not determine the direction of acceleration

true

projectile

an object that has been projected into the air or dropped and is only acted on by the forces of gravity and air resistance

the horizontal displacement of a projectile is determined by what 3 things

- initial horizontal velocity
- initial vertical velocity
- initial height

what is the optimal projection angle for maximizing the horizontal displacement of a projectile that’s release height is zero and whos resultant velocity is the same no matter what the projection angle?

45 degrees

center of gravity

the point at which the entire mass or weight of the body may be considered to be concentrated

“ the point of balance”