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AP Physics Unit 1: Kinematics

Terms in this set (44)

Frame of Reference
A framework that is used for the observation and mathematical description of physical phenomena and the formulation of physical laws.
Dynamics
explains the causes of motion
Kinematics
Describes motion
Distance
How far an object moves/total ground it covers (scalar quantity)
Scalar Quantity
Defined by magnitude or volume
Displacement (x)
Distance and direction with respect to the origin
Vector Quantity
Requires magnitude and direction
Average Speed
Distance per time
Equation for speed
S=(d/t)
Average Velocity (v)
Displacement per time
Change in Displacement Formula
∆x=(xf)-(x0)
Equation for Velocity
V=((∆x)/t)
Constant Displacement
∆x=0, v=0
Constant Velocity
Linear relationship where x changes with respect to time. Positive velocity moves forward, up, or right. Negative velocity moves backward, down, or left.
Displacement Formula
∆x=v*t
Acceleration (a)
A change in velocity over a time interval.
When is an object speeding up?
When velocity and acceleration have the same sign.
When is an object slowing down?
When velocity and acceleration have opposite signs.
Equation for Acceleration
a=((∆v)/t)
Equation for Change in Velocity
∆v=(vf)-(v0)
Constant Acceleration
The velocity changes regularly with respect to time. Since the velocity is changing, the slope must change, causing for a curved line (parabolic relationship).
What does the slope of a velocity graph tell you?
The acceleration of that object.
What does the area under the curve of a velocity graph tell you?
The displacement of an object.
A graph that is concave up has (...) acceleration
Positive
A graph that is concave down has (...) acceleration
Negative
What equation uses...
V0
∆x
1/2
Vf
t
∆x=.5((v0)+(vf))t
What equation uses...
V0
t
a
t^2
∆x
.5
∆x=((v0)t) + .5at^2
What equation uses...
a
Vf
t
V0
Vf=(v0) + at
What equation uses...
V0^2
2
Vf^2
∆x
a
Vf^2=(v0^2)+2a∆x
Free Fall
Object acts under the influence of gravity alone. Assumes air resistance is negligible. Gravity is a constant force.
What is the acceleration due to gravity?
g=-9.8 m/s^2
For free fall, what can you do to the equations to constant acceleration?
Substitute -9.8 in for a. Substitute ∆y in for ∆x (height).
What is always important to remember of the x and y planes?
They are independent of each other.
Horizontal Component (x)
Constant Velocity
Vertical Component (y)
Constant acceleration due to the force of gravity
Why is the path of a projectile always a parabola?
∆x remains constant (constant velocity) while ∆y changes exponentially (due to acceleration)
Constant Velocity Trigonometric Equation
Vx=(V0)*cos(Θ)
Initial Velocity Trigonometric Equation
V0y=(V0)*sin(Θ)
X-Motion
Constant velocity. Definition of Velocity Equation: ∆x=(Vx)t
Y-Motion
Constant acceleration due to gravity. Free fall equations.
What is the only similar thing between the x and y planes?
Time
Range (∆x)
Horizontal displacement. It is dependent on the launch velocity and angle (Vx)
What angle allows for maximum range?
45º
Complimentary Angles
Sum of two angles is 90º.
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