BIZOMAT MAKEOS · Mechanics

Inclined Plane and Friction

What force pushes, holds or lowers a load on this slope?

Force parallel to an incline needed to raise, hold and lower a load with sliding friction, with efficiency and a self-locking check.

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How this tool works

Inputs, units and where to find them

InputUnitTypical source
Load masskgMass of the load including any carrier or pallet.
Incline angle°Slope of the plane from horizontal.
Coefficient of sliding frictionSliding (kinetic) friction coefficient for the two surfaces, measured or from a supplier; use static friction for break-away.

What each input means

Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.

What this means: Load mass
Illustration: Load massA weight resting on a scale; Load mass is how much matter it contains, in kilograms or grams.mExample: 200 kgLoad mass
What it is
The mass of everything that slides on the slope: the load plus any pallet, carrier or sled. The tool turns it into a weight using standard gravity.
Units and format
Enter a number in kg: kilograms. The form accepts 0.000001 kg to 10000000 kg. Required: the tool does not calculate until every input is valid.
Example
The form opens with 200 kg as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Every force result rises in proportion to the mass.
Get it right
Enter mass in kg, not a weight in newtons.
What this means: Incline angle
Illustration: Incline angleTwo lines meeting at a point with an arc between them, marking the angle Incline angle.θExample: 15°Incline angle
What it is
The slope of the plane, measured from horizontal: 0° is level and larger angles are steeper.
Units and format
Enter a number in °: degrees of angle. The form accepts 0° to 89.9°. Required: the tool does not calculate until every input is valid.
Example
The form opens with 15° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Get it right
Measure from horizontal, not from vertical. A slope given as a percentage or ratio must be converted to degrees first.
What this means: Coefficient of sliding friction
Illustration: Coefficient of sliding frictionA block resting on a surface with the normal force pressing down and friction resisting sliding; Coefficient of sliding friction is friction force divided by normal force.NfrictionμExample: 0.3Coefficient of sliding friction
What it is
The coefficient of friction between the load and the surface it slides on: friction force divided by the force pressing the surfaces together.
Units and format
Enter a plain number with no unit. The form accepts 0 to 3. Required: the tool does not calculate until every input is valid.
Example
The form opens with 0.3 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Higher friction raises the force to push up and decides whether the load holds by itself on the slope.
Get it right
Use the sliding (kinetic) value for steady movement and the static value for the force to start it moving; both come from tests or supplier data.

Method and formulas

  1. Weight W = m g with g = 9.80665 m/s².
  2. Raise: F = W(sin θ + μ cos θ). Hold: F = W(sin θ − μ cos θ). Lower: F = W(μ cos θ − sin θ).
  3. Self-locking when μ ≥ tan θ. Efficiency raising = sin θ ÷ (sin θ + μ cos θ).
  4. Example: 200 kg on a 15° slope with μ = 0.3 needs 1,076 N to push it up.

Limitations

  • Force parallel to the plane; rolling resistance and acceleration forces are not included.
  • Friction coefficients vary widely with surface condition and lubrication.
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Size a pusher, winch or cylinder for a ramp
  • Check whether a load slides on a chute
  • Estimate efficiency of a sliding lift

Who it is for

  • Design engineers
  • Maintenance engineers
  • Technicians

What you get

  • Force to push up the slope
  • Force to hold the load
  • Force to pull it down
  • Efficiency raising
  • Self-locking or not

Interpreting the result

  • Use the break-away (static) coefficient to size a drive that must start the load.

References

  • Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 165–171. Topic reference; no source tables or recommended settings are reproduced.

Learn the Concepts Behind This Tool

These BIZOMAT Library readings explain the method this tool uses, with worked examples.

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Open the Inclined Plane and Friction calculator