1. What Is The Resistive Force Formula?

The resistive force formula \( F_r = - b v \) describes a linear damping force where the resistive force is proportional to the velocity of an object moving through a fluid or viscous medium. The negative sign indicates that the force opposes the direction of motion.

2. How Does The Calculator Work?

The calculator uses the resistive force formula:

Where:

• \( F_r \) — Resistive force (N)
• \( b \) — Damping coefficient (N·s/m)
• \( v \) — Velocity (m/s)

Explanation: This formula represents a linear damping model where the resistive force increases proportionally with velocity. The damping coefficient 'b' depends on the properties of the fluid and the object's shape and size.

3. Importance Of Resistive Force Calculation

Details: Calculating resistive forces is essential in engineering, physics, and fluid dynamics for designing systems that involve motion through fluids, predicting object trajectories, analyzing damping in mechanical systems, and understanding energy dissipation.

4. Using The Calculator

Tips: Enter the damping coefficient in N·s/m and velocity in m/s. The damping coefficient must be positive, while velocity can be positive or negative depending on direction.

5. Frequently Asked Questions (FAQ)

Q1: What is the physical meaning of the negative sign?
A: The negative sign indicates that the resistive force always acts in the direction opposite to the velocity, opposing the motion.

Q2: When is this linear damping model applicable?
A: This model is valid for low Reynolds numbers where viscous forces dominate, typically for slow-moving objects in highly viscous fluids.

Q3: What are typical values for damping coefficients?
A: Damping coefficients vary widely depending on the medium and object. In air, values might be 0.1-10 N·s/m, while in water or oil, values can be 10-1000 N·s/m or higher.

Q4: How does this differ from quadratic drag?
A: Linear damping assumes force proportional to velocity (F ∝ v), while quadratic drag assumes force proportional to velocity squared (F ∝ v²). Quadratic drag is more common at higher velocities.

Q5: Can this formula be used for air resistance?
A: For most practical situations involving air resistance at normal speeds, quadratic drag is more appropriate. Linear damping is mainly used for very slow motions in viscous fluids.