2.1 
Jump to Book CoverPrevious Page
Next Page

Videos:
Interactive Simulations   Position and displacement in one dimension    Displacement and position in two dimensions    Solve v=dx/dt for dt    Velocity, position, and time (basic version)    Velocity, position, and time (more advanced version)    Acceleration (basic version)    Acceleration (more advanced version)    Static equilibrium    Static equilibrium and the lever    Newton's second law (basic version)    Newton's second law (more advanced version)    Circular motion interactive simulation    Orbits of the planets and dwarf planets    Orbits simulation Interactive Calculators   Speed calculator    Velocity calculator    Acceleration calculator    Velocity in accelerated motion    Average velocity calculator    Hooke's law calculator    Torque calculator    Rotational equilibrium and torque    Newton's second law calculator    Momentum calculator    Angular velocity    Linear velocity and angular velocity    Centripetal acceleration    Centripetal force    Law of universal gravitation calculator
1 - Science of Physics
2 - Forces and Motion      Chapter 2 at a glance      2.1 - Motion      2.2 - Force, momentum, and Newton's laws      2.3 - Circular motion      2.4 - Solving harder physics problems      2.5 - Chapter review3 - Energy Transformations4 - Waves and Sound
5 - Electricity and Magnetism
6 - Light and Optics
7 - The Atom
8 - Linear Motion
9 - Vectors and Forces
10 - Forces
11 - Newton's Laws and Gravitation
12 - Circular Motion and Gravitation
13 - Torque and Static Equilibrium
14 - Momentum and Collisions
15 - Angular momentum
16 - Power and Machines
17 - Harmonic Motion
18 - Waves
19 - Sound
20 - Electricity
21 - Electric and Magnetic Fields
22 - Electromagnetism and Induction
23 - Light and Color
24 - Geometrical Optics
25 - Electromagnetic Radiation
26 - The Properties of Matter
27 - Thermodynamics and Heat Transfer
28 - The Atom
29 - The Quantum Theory
30 - TBD
31 - TBD
32 - TBD
33 - TBD
34 - TBD
35 - TBD
36 - TBD
37 - The atomic nucleus and radioactivity
38 - Nuclear reactions
39 - Relativity
40 - Particle physics and the standard model
41 - Electronics (semiconductors)
42 - Nuclear technology
43 - Lasers and photonics
44 - Metals, alloys and materials science
45 - Communications technology
46 - Buildings and structures
47 - Energy technology
48 - Biophysics
49 - Matter and Energy, Space and Time
50 - Energy Transformations
51 - Nanotechnology
52 - Website Videos
53 - ExtraStuff
55 - Modeling Motion, Friction, and Center of Mass
56 - Work and the Conservation of Energy
2A: Velocity, position, and time
How do we predict an object's position at a later time?
Equations can be models that allow us to predict a future value, such as position, from given information, such as velocity and starting point. Most models have parameters, such as initial position and velocity, which are adjusted to fit a specific situation or problem. In simple cases these parameters, sometimes called constants, can have a single value for the entire problem. In more realistic cases the constants are also adjusted in steps so the model can fit more complex motion.
Part 1: The constant velocity model for position vs. time

How to use the velocity, position, and time simulation
  1. The interactive model shows position and velocity versus time graphs. Red circles on the position vs. time graph are “targets.” Your goal is to adjust the initial parameters, xi and v, so the line hits both targets.
  2. [Run] starts the simulation. [Stop] stops it without changing values. [Clear] resets all variables to zero. [Reset] resets all variables and sets new targets.
  3. Enter values in the white boxes. Grey boxes are calculated and cannot be edited. The top score of 100 is achieved by hitting the center of each target.
  1. Describe the meaning of xi and v.
  2. What velocity will move an object from +50 m to −50 m in 20 seconds?
Velocity, position, and time (basic version) In this interactive simulation, you will adjust the initial position xi and velocity v of the ErgoBot so that it passes through the targets the position vs. time graph.
Part 2: A more complex model

How to use the advanced velocity, position, and time simulation
  1. The second interactive model contains four constant speed segments.
  2. Your goal is to adjust the values of xi and v for all sections to hit the four targets.
  3. Enter values in the white boxes. The top score of 100 is achieved by hitting the center of each target.
  1. Where do the values of xi in the grey boxes come from?
  2. Describe how this model could be used to recreate any motion in one dimension.
Velocity, position, and time (more advanced version) In this interactive simulation, you will adjust the initial position xi and four different velocities v—for each of four time periods—of the ErgoBot so that it passes through the targets the position vs. time graph.

56 Previous Page Next Page