Kinematics Unit Review Flashcards
Scalar Quantity
Has magnitude (size) but no direction. Ex. 250m
Vector Quantity
Has magnitude and direction. 250m [West]
Usually indicated with a variable and an arrow.
Can be shown graphically or mathematically.
Distance (d)
The length of the path between locations (scalar).
Position (d vector)
The distance and direction of object from reference point. (vector).
Displacement (▲d vector)
The change in position of an object.
Vectors in 2 Dimensions
To add vectors that are not in a straight line we can use 2 approaches: Draw Scale Diagram, Trig
Speed (v)
Distance per unit time. Formula - v =d/t (m/s km/h). [Avg. total distance / total time]
Velocity (v vector)
Displacement per unit time. v vector = ▲d /▲t
Acceleration (a vector)
The rate of change in velocity per unit time. a = ▲v /▲t or a = v2-v1 / ▲t. Units m/s².
Tangent Method
Tangents - line brushes curve. Calculate slope of tangent to get instantaneous velocity. Graph velocity and find the slope which = acceleration
Uniform Acceleration Formula (no d)
a = v2-v1 / ▲t
Uniform Acceleration Formula (no a)
▲d = (v1+v2 / 2) ▲t
Uniform Acceleration Formula (no v2) (no v1)
d = v1 t + ½ a t² . d = v2 t - ½ a t²
Uniform Acceleration Formula (no t)
v2² = v1² + 2ad
Acceleration Near Earth’s Surface
Acceleration due to gravity (g vector) is constant for any object. g = 9.81 m/s² [Down] if given g value, multiply 9.81g value
