Exam 1 Flashcards
(47 cards)
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”
a womans center of gravity is ___% of her height from the ground
55% - because women tend to have wider pelvic bones and narrower shoulders
a mans center of gravity is approximately ____% of his height from the ground
57%
infants have _____ centers of gravity relative to their height because of their relatively larger heads and shorter legs
higher centers of gravity
stability
the capacity of an object to return to equilibrium or to its original position after being displaced
true or false: the height of the center of gravity stays the same
true
true or false: the height of the center of gravity within a system goes up but vertical jump height decreases
true
