Solve inclined plane motion with friction
Edit values to solve for the highlighted result field.

An inclined plane is one of those “simple machine” ideas that shows up everywhere: ramps, loading docks, wheelchair access, and even the wedge under a door. This calculator helps you answer practical questions like:
Note on object types: in this calculator, “Cubic block” includes sliding friction (so you can model energy loss). Rolling objects (ball, sphere, cylinder, hoop, torus) are modeled as rolling without slipping.
Want to isolate friction effects? Try the Friction Calculator. If your slope is effectively vertical, the Free Fall Calculator can be a better fit.
If you switch the object type (say from Ball to Torus), the calculator clears the Results fields so you don’t accidentally carry over a solution from a different physics model.
Inputs: , , , , , .
1) Convert height to ramp length
2) Acceleration with friction
3) Time and final velocity (starting from rest)
4) Energy loss (shown for cubic block)
Interpretation: if friction is present, not all potential energy ends up as translational kinetic energy — the missing energy is commonly dissipated as heat and sound.
An inclined plane is a flat surface that’s tilted by an angle relative to the ground. In day-to-day life it shows up as ramps, loading platforms, and wedges.
The “simple machine” idea is that lifting an object to a height can be made easier by spreading the work over a longer distance .
From a side view, an inclined plane is a right triangle. That’s why you can convert between height, length, and angle:
For a sliding block, friction reduces the net downslope drive. The core acceleration model is:
Once you know and , you can solve time and final velocity using kinematics:
If , the block won’t slide down on its own. In that case the calculator warns you because the static friction limit is enough to hold the object.
Energy loss (displayed for cubic block) is estimated as the difference between the drop in potential energy and the gain in translational kinetic energy:
For rolling objects, friction plays a different role: it prevents slipping and enables rotation. A very convenient result is that the acceleration can be written as:
The factor depends on the object shape:
Time and final velocity still use the same kinematics equations as the block case.
Curious about inertia? The Polar Moment of Inertia Calculator can help build intuition for how “hard it is to spin” different shapes.
Using the same inputs as the quick example above, the calculator gives:
How to use the result: if you’re designing a safe run-out zone at the bottom, the final speed helps you estimate stopping distance and impact energy.
If is small and is large, the block may not move. For example, with and , the drive term becomes negative, so the calculator will warn that the body won’t slide down.
As and , the motion approaches free fall. In that case, it’s often clearer to use the Free Fall Calculator directly.
Suppose a solid ball rolls from rest down a ramp with and height .
For a solid ball the factor is , so:
💡 Key insight: Compared to a frictionless sliding block on the same ramp, a rolling object accelerates more slowly because some energy goes into rotation.
Background: you want to estimate how quickly a cart could roll down a ramp. Inputs: choose a rolling object (e.g. Ball), set , , and . Result: read and plan for safe spacing.
Background: a steeper slide increases the final speed. Inputs: use Cubic block and set to approximate surface friction. Result: use as a simple “risk indicator” for how fast riders might reach the bottom.
Background: you’re trying to choose between a steeper ramp (short) and a gentler ramp (long). Inputs: set the same , vary , and compare the required force along the ramp. Tip: if friction matters, also try the Friction Calculator.
Background: compare how different shapes roll. Inputs: keep and fixed, then switch object types. Result: compare , , and .
If you’re modeling a real surface and you have experimental data (like a measured “just starts to slip” angle), you can estimate and then plug it into the cubic block model.
It spreads the same elevation gain over a longer distance . The required force along the ramp is a fraction of the weight, roughly proportional to (plus friction if present).
For a sliding block with friction, use:
If you know and , and the object starts from rest, you can estimate:
With an initial speed , the calculator uses .
The downslope component of gravity is , which grows as increases. For rolling objects, the same trend holds, but divided by a shape factor .
If you can measure the largest angle where the object stays still, a common approximation is:
For more friction-focused problems, use the Friction Calculator.
Have a look at the flight path of the object with this trajectory calculator.
Calculate free fall parameters including gravitational acceleration, drop height, fall duration, and impact velocity. Supports bidirectional LRU solving with unit conversions.
Calculate free fall with quadratic air drag, including terminal velocity, fall time, maximum velocity, and drag force. Supports air resistance coefficient calculation from object properties.
Calculate the horizontal range of a projectile based on velocity, angle, and initial height. Supports bidirectional calculation with multiple unit systems.
Calculate projectile trajectory parameters including launch velocity, angle, distance, maximum height, and flight time with bidirectional solving.
Use this maximum height calculator to figure out what is the maximum vertical position of an object in projectile motion.