PHYSICS Section 1

Nota:

• -Measurement in Physics is based on measurement of physical quantities.  -Certain physical quantities have been chosen as base quantities (such as length, time, and mass); each has been defined in terms of a standard and given a unit of measure (such as meter, second, and kilogram).  -Other physical quantities are defined in terms of the base quantities and their standards and units.

1. LENGTH

   Nota:

   • The meter is defined as the distance traveled by light during a precisely specified time interval
2. TIME

   Nota:

   • The second is defined in terms of the oscillations of light emitted by an atomic (cesium-133) source. Accurate time signals are sent worldwide by radio signals keyed to atomic clocks in standardizing laboratories.
3. MASS

   Nota:

   • The kilogram is defined in terms of a platinum– iridium standard mass kept near Paris. For measurements on an atomic scale, the atomic mass unit, defined in terms of the atom carbon-12, is usually used.
4. DENSITY

   Nota:

   • The density rho of a material is the mass per unit volume:  rho = m / V .

1. POSITION

   Nota:

   • -The position x of a particle on an x axis locates the particle with respect to the origin, or zero point, of the axis.  -The position is either positive or negative, according to which side of The origin the particle is on, or zero if the particle is at the origin.  -The positive direction on an axis is the direction of increasing positive numbers; the opposite direction is the negative direction on the axis.
2. DISPLACEMENT

   Nota:

   • The displacement x of a particle is the change in its position: DELTA X = X2 - X1 Displacement is a vector quantity. It is positive if the particle has moved in the positive direction of the x axis and negative if the particle has moved in the negative direction.
3. AVG VELOCITY

   Nota:

   • When a particle has moved from position x1 to position x2 during a time interval t t2 t1, its average velocity during that interval is  Vavg = DELTA X / DELTA t -The algebraic sign of vavg indicates the direction of motion (vavg is a  vector quantity).  -Average velocity does not depend on the actual distance a particle moves, but instead depends on its original and final positions. -On a graph of x versus t, the average velocity for a time interval t is the slope of the straight line connecting the points on the curve that represent the two ends of the interval.
4. SPEED

   Nota:

   • The average speed savg of a particle during a time interval t depends on the total distance the particle moves in that time interval:  Savg = total distance / DELTA t
5. INST VELOCITY

   Nota:

   • The instantaneous velocity (or simply velocity) v of a moving particle is: V = (THE LIMIT AS t = 0) OF DELTA X / DELTA t  IS ALSO EQUAL TO V =  dx / dt
   • The instantaneous velocity (at a particular time) may be found as the slope (at that particular time) of the graph of x versus t. Speed is the magnitude of instantaneous velocity.
6. AVG ACCELERATION

   Nota:

   • Average acceleration is the ratio of a change in velocity DELTA v to the time interval DELTA t in which the change occurs: Aavg = delta x / delta t
7. Instantaneous Acceleration

   Nota:

   • a = dv / dt = d^2x / dt^2
   1. On a graph of v versus t, the acceleration a at any time t is the slope of the curve at the point that represents t.
8. Constant Acceleration

   Nota:

   • describe the motion of a particle with constant acceleration
   • These are not valid when the acceleration is not constant.
   1. V = Vo + at
   2. X - Xo = Vot + (1/2)at^2
   3. V^2 = V0^2 + 2a(X-Xo),
   4. X - Xo = (1/2)(Vo - V)t
   5. X - Xo = vt - (1/2)at^2
9. Free-Fall Acceleration

   Nota:

   • An important example of straightline motion with constant acceleration is that of an object rising or falling freely near Earth’s surface.The constant acceleration equations describe this motion, but we make two changes in notation: (1) we refer the motion to the vertical y axis with y vertically up; (2) we replace a with g, where g is the magnitude of the free-fall acceleration.  Near Earth’s surface, g = 9.8 m/s2 ( 32 ft/s2).
   1. g
      = 9.8 m/s2

1. Scalars and Vectors
   1. Vectors have both magnitude and direction
2. Adding Vectors Geometrically
3. Components of a Vector
   1. ax  = a cos THETA
   2. ay =  a sin THETA
   3. Magnitude of a vector
      1. a = sqrt( ax^2 + ay^2)
   4. Orientation of vector
      1. tan THETA = ay / ax
4. Product of a Scalar and a Vector
5. The Scalar Product
6. The Vector Product
7. Adding Vectors in Component Form
8. Unit-Vector Notation

1. Position Vector
2. Displacement
3. Avg Velocity and Inst Velocity
4. Avg Velocity and Inst Velocity
5. Projectile Motion
6. Uniform Circular Motion
7. Relative Motion

1. Force
2. Newton’s First Law
3. Mass
   1. Fg = weight = mg
4. Newtonian Mechanics
   1. Inertial Reference Frames
5. Newton’s Second Law
6. Some Particular Forces
7. Newton’s Third Law

1. Friction
2. Drag Force
3. Terminal Speed
4. Uniform Circular Motion

1. Kinetic Energy
2. Work
   1. Work Done by a Constant Force
3. Work and Kinetic Energy
4. Work Done by the Gravitational Force
5. Work Done in Lifting and Lowering an Object
6. Spring Force
   1. Work Done by a Spring Force
7. Work Done by a Variable Force
8. Power

1. Conservative Forces
2. Potential Energy
3. Elastic Potential Energy
4. Mechanical Energy
5. Potential Energy Curves
6. Gravitational Potential Energy
7. Work Done on a System by an External Force
8. Conservation of Energy
9. Power

1. Center of Mass
2. Newton’s Second Law for a System of Particles
3. Linear Momentum and Newton’s Second Law
4. Collision and Impulse
5. Variable-Mass Systems
6. Conservation of Linear Momentum
7. Inelastic Collision in One Dimension
8. Elastic Collisions in One Dimension
9. Collisions in Two Dimensions

1. Angular Position
2. Angular Displacement
3. Angular Velocity and Speed
4. Angular Acceleration
5. The Kinematic Equations for Constant Angular Acceleration
6. Linear and Angular Variables Related
7. Rotational Kinetic Energy and Rotational Inertia
8. The Parallel-Axis Theorem
9. Torque
10. Newton’s Second Law in Angular Form
11. Work and Rotational Kinetic Energy

1. Rolling Bodies
2. Torque as a Vector
3. Angular Momentum of a Particle
4. Newton’s Second Law in Angular Form
5. Angular Momentum of a System of Particles
6. Angular Momentum of a Rigid Body
7. Conservation of Angular Momentum
8. Precession of a Gyroscope