Kinematics
Mathematical description of motion without regard to cause. How are position, velocity and acceleration related, both graphically and analytically?
Start out with one-dimensional motion.
W. P. Beyermann
Fall 2007
1
Sign Convention
W.
Physics 2A
General Physics (Classical Mechanics)
Prof. Beyermann
W. P. Beyermann
Fall 2007
1
Introduction
What is Physics?
Webster's definition a science that deals with matter and energy and their interactions in the fields of mechanics, acous
Motion in a Circle
For uniform circular motion, the acceleration is constant and always points toward the center of rotation. This is called centripetal acceleration, and its magnitude is v2/r.
W. P. Beyermann
Fall 2007
1
Uniform Circular Motion
Force and Motion
What is a force, and how do you identify all the forces acting on an object (i.e., the force body diagram)?
An object's acceleration is proportional to the net force acting on the object (i.e., Newton's 1st and 2nd laws the cause
Interacting Objects Newton's 3rd Law
For every force on an object, there is a force on another object that is equal in magnitude and opposite in direction. How do you identify these paired forces? Paired forces never act on the same object.
W. P
Motion with Constant Acceleration
Assume si = 0; and vis and as > 0
W. P. Beyermann Fall 2007
Kinematics
1
vs v fs - vis as = = v fs = vis + as t t t
(1)
s f = si + area under the velocity curve vs between ti and t f
s f = si + vis t + 1 as (t
Elastic and Inelastic Collisions
(Includes Pre Lab Assignment)
This week we will study elastic and inelastic collisions on the air track. You will record the velocity of gliders
before and after collisions, and calculate the changes in momentum and kineti
Physics 2LA
Acceleration Due To Gravity
(Contains prelab assignment)
This laboratory involves an experimental determination of a value for the acceleration due to
gravity at the surface of the earth, g. You will determine g over different fall distances,
Newtons Second Law
(Pre-lab Assignment included)
This week we will make measurements of the relationship between Force and Acceleration, or Newtons
second law, i.e.,
The lab will consist of two separate sets of measurements:
Vary m keeping F constant, and
Measurements & Error Analysis
(Includes Pre Lab Assignment)
Objective
To learn the skill of performing careful measurements, understanding the nature of errors that occur during
measurements, keep track of significant figures, use some basic data analysis
Projectile Motion
Projectile an object that moves in two-dimensions under the influence of only the gravitational force. a x = 0 v x = constant
ay = -g
Uniform motion in the horizontal direction, and free fall motion in the vertical direction.
Pr
Developing a Good Problem-Solving Strategy
Representations of Knowledge
Verbal representation Pictorial representation Physical representation Graphical representation Mathematical representation
W. P. Beyermann
Fall 2007
1
Pictorial Repres
Newton's Theory of Gravity
When the motion's displacement is small relative to the distance between the object and the Earth, the gravitational force is directed downward and is approximately constant. When the motion's displacement is comparable t
Dynamics of Uniform Circular Motion
For uniform circular motion, a force, whose magnitude is constant, but its direction always points from the object to the center of rotation, is needed to provide the centripetal acceleration.
W. P. Beyermann
Fal
Example: A Block on a Vertical Wall with Friction
A 3.0 kg block is pressed against a vertical wall by a force that makes an angle of 30 from the horizontal. The kinetic coefficient of friction between the block and wall is 0.40. What magnitude of fo
Dynamics
Identify Individual Forces Acting on Object
Determine the Net Force
Use Newton's Law to Determine Acceleration
Use Kinematics to Determine Object's Motion Full Problem-Solving Strategy
W. P. Beyermann
Fall 2007
1
Problem Solving Strat
Motion in Two Dimensions
The kinematic equations are vector equations, so the motion in orthogonal directions is independent of each other.
W. P. Beyermann
Fall 2007
1
Kinematics in Two-Dimension
Review Position:
^ j r = xi + y^
^ Displacement
Friction & Drag
Friction opposes motion, except in the case of the force of propulsion. The static frictional force is directed opposite to the applied force, and its magnitude matches the applied force, up to a maximum value of sn where n is the no
Concepts of Motion
How do you visualize motion?
During this lecture, we will examine motion in detail. We will start with a literal picture and proceed to a much more abstract representation, containing a small subset of the system's characteristics
Vectors and Scalars
What is a vector and how do you add and subtract them, both graphically and analytically?
A scalar is a quantity that is completely specified by a positive or negative number. A vector has a magnitude, which is always a positive
The Language of Motion
How do you quantitatively describe motion in terms of position, displacement, velocity, speed and acceleration?
W. P. Beyermann
Fall 2007
1
Example: Sandy walks to class
Sandy, who is a student in Physics 2A, is in her dor
Projectile Motion
(Pre Lab Assignment Included)
Objective:
This laboratory investigates the motion of projectiles under the influence of gravity.
You will do two experiments:
1.
Measure the projectiles range and time-of-flight as a function of launching a