Rolling Resistance Calculator
Calculate rolling resistance force and related parameters for objects on various surfaces
Rolling resistance is the force that resists the motion of a rolling object, such as a wheel or ball, on a surface. It occurs due to:
- Deformation of the rolling object
- Deformation of the surface
- Surface adhesion
- Micro-sliding between surfaces
Understanding rolling resistance is crucial in vehicle design, transportation efficiency, and energy consumption calculations.
Surface Properties
- Surface material and texture
- Surface hardness and elasticity
- Surface conditions (wet, dry, temperature)
Object Properties
- Weight and mass distribution
- Material properties
- Geometry and dimensions
Operating Conditions
- Speed of motion
- Temperature
- Load conditions
Rolling Resistance Force
F_r = C_rr × N
Where:
- F_r = Rolling resistance force
- C_rr = Coefficient of rolling resistance
- N = Normal force
Normal Force
N = mg × cos(θ)
Where:
- m = Mass of the object
- g = Acceleration due to gravity
- θ = Incline angle
Power Loss
P = F_r × v
Where:
- P = Power loss
- F_r = Rolling resistance force
- v = Velocity
Example 1: Car on Concrete
- Vehicle mass: 1500 kg
- Surface: Concrete (C_rr = 0.013)
- Speed: 20 m/s
- Rolling resistance: 191.3 N
- Power loss: 3.83 kW
Example 2: Bicycle on Gravel
- Total mass: 85 kg
- Surface: Gravel (C_rr = 0.02)
- Speed: 5 m/s
- Rolling resistance: 16.7 N
- Power loss: 83.5 W
How does rolling resistance affect fuel efficiency?
Rolling resistance directly impacts fuel consumption as it requires additional energy to overcome. Lower rolling resistance means better fuel efficiency.
Why do different surfaces have different coefficients?
Surface coefficients vary due to material properties, texture, and hardness. Harder, smoother surfaces generally have lower rolling resistance coefficients.
How can rolling resistance be reduced?
Rolling resistance can be reduced by using harder materials, maintaining proper tire pressure, choosing smoother surfaces, and optimizing wheel design.