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Linear Resistive Force Formula:
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Linear resistive force describes the opposition to motion that is directly proportional to velocity. This model is commonly used in physics to represent damping forces in mechanical systems, air resistance at low speeds, and viscous drag in fluids.
The calculator uses the linear resistive force formula:
Where:
Explanation: The negative sign indicates that the resistive force always opposes the direction of motion. The magnitude of the force increases linearly with velocity.
Details: Accurate calculation of resistive forces is essential for designing mechanical systems, predicting motion in fluid environments, analyzing damping in oscillatory systems, and understanding energy dissipation in various physical scenarios.
Tips: Enter the damping constant in N·s/m and velocity in m/s. The damping constant must be positive, while velocity can be positive or negative depending on direction.
Q1: When is the linear resistive force model applicable?
A: This model works well for low velocities where resistance is proportional to speed, such as viscous drag in laminar flow or light damping in mechanical systems.
Q2: What are typical values for the damping constant k?
A: Values vary widely depending on the system - from small values (0.1-1 N·s/m) for light air resistance to large values (10-100 N·s/m) for viscous fluids or heavy damping.
Q3: How does this differ from quadratic air resistance?
A: Linear resistance assumes force ∝ velocity, while quadratic resistance (F ∝ v²) is more accurate for higher speeds and turbulent flow conditions.
Q4: Can the velocity be negative?
A: Yes, negative velocity indicates motion in the opposite direction, which will result in a positive resistive force (opposing the negative velocity).
Q5: What real-world systems use this model?
A: Dashpots in vehicle suspensions, door closers, precision instruments with air damping, and low-speed fluid flow calculations often employ linear resistance models.