Kinematics Flashcards
Chapter 3
Kinematics
The branch of physics that deals with objects in motion without considering the forces that cause the motion
Motion
When a body does not change its position with time, we can say that the body is at rest, while if a body changes its position with time
Translational (Linear) Motion
A type of motion in which all parts of an object move the same distance in a given time
-Rectilinear motion refers to motion along a straight line.
Ex: An object thrown in the air follows a parabolic trajectory.
-Curvilinear motion refers to motion along a curved path. can be circular, parabolic, or any other type of curve. Ex: A person walking in a straight line.
Rotational Motion
When an object moves about an axis and different parts of it move by different distances in a given interval of time
Ex: A spinning top, a rotating wheel, or the Earth spinning about its own axis.
Circular Motion
Motion that refers specifically to the motion of an object along a circular path.
-Can be uniform (constant speed) or non-uniform (changing speed).
-In circular motion, the object is moving around a fixed point
-Typically analyzed in terms of its tangential speed and centripetal acceleration.
Ex: A car moving along a curved road, or a planet orbiting the sun.
Oscillatory (Vibratory) Motion
A specific periodic motion that involves the to and fro movement of a body
Directions/Dimensions
-One Dimensional Motion is the motion of a particle moving along a straight line
-Two-dimensional Motion is a particle moving along a curved path in a plane
-Three-dimensional motion describes particles moving randomly in space
Sate of Motion
-Uniform Motion: When a body travels equal distances in equal intervals of time
-Non-uniform Motion: When a body travels unequal distances in equal time intervals
Displacement
The distance moved by a body in a specific direction
-d =df−di
-df: Final position
-di: Initial position
-d: Displacement
-d = (dx,dy)(for2Dmotion)
_________
-2D Magnitude ∣d∣ = /dx²+dy²
-d =( dx,dy,dz)(for3Dmotion)
______________
-3D Magnitude ∣d ∣= /dx² +dy²+dz²
-d(t)=∫∫a(t)dt
Velocity
The rate of change of displacement in a given direction
v = Δx = xf -xi = displacement
Δt tf - ti change in time
-v(t) = dx
d(t)
-v(t)=∫a(t)dt
Instantaneous Velocity
v = Δx
Δt
Average Velocity
a = Δx = vf -vi
Δt = tf - ti
Acceleration
The rate of change of velocity
a = change in velocity = (v - u)/2
time
a = dx = d2x
d(t) d2(t)
1st Equation of Motion
(1)a = v - u
t
(2)v = u + at
2nd Equation of Motion
(1) s = (v + u)t -v = u + at
( t )
s = (u + at + u)t
2
s = (2u + at)t
2
s = ut + 1/2at²