2.2 
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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
2D: Static equilibrium
How do we predict when something will move or not?
How do we determine forces we cannot measure?
Objects remain at rest only when the net force and the net torque are zero. The converse is also true: if an object is at rest you know the net force and the net torque must be zero. This last fact is used to determine unknown forces while the first statement predicts whether an object will remain at rest or begin to move.
Part 1: A simply supported beam

Static equilibrium simulation for masses placed on a beam supported at both ends
  1. Ths interactive model allows you to place up to four masses on a beam that is supported at its ends. You can adjust the placement of the masses by entering distances for each one.
  2. [Reset] clears all the masses and distances.
  3. The [Force] or [Torque] button toggles between displaying the force or torque diagrams below the bar.
  1. What is the relationship between the upwards and downwards forces on the free-body diagram?
  2. What is the relationship between the clockwise and counterclockwise torques when measuring torques?
  3. Create an equilibrium in which a force scale under the left support will measure a force of 300 N.
Static equilibrium In this interactive simulation, you will explore free-body force diagrams for static equilibrium.
Part 2: A lever

Static equilibrium simulation for masses on a balance (or see-saw)
  1. The interactive model allows you to place the same four masses on a lever that is free to tip one way or the other.
  2. [Reset] clears all the masses and distances.
  3. The [Force] or [Torque] button toggles between displaying the force or torque diagrams below the bar.
  1. Why is the lever harder to balance than the beam in the first part?
    Why can the lever not be balance when the fulcrum is on one end?
  2. How can the direction of tipping be predicted?
  3. Create a situation in which the net torque is +100 Nm and another in which the net torque is −100 Nm. What happens to the lever in either case? Does it tip clockwise or counterclockwise?
Static equilibrium and the lever In this interactive simulation, you will explore static equilibrium using a simple lever found in playground equipment such as a see-saw.

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