Inclined Plane Calculator

Resolves the forces on a block on a slope.

Acceleration down the slope

— m/s²

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Weight along the slope —

Normal force —

Friction available —

Force to push it up at steady speed —

Angle at which it starts to slide — °

Reading this —

The formula

along the slope = m g sin θ normal force = m g cos θ a = g (sin θ − μ cos θ)

Gravity is split into a part along the slope and a part into it. Friction opposes the first and depends on the second.

Mass cancels out of the acceleration, so a heavy and a light block with the same μ slide the same way.

How fast does a block slide down a 30° slope?

With μ = 0.2, 3.2 m/s². Without friction, 4.9 m/s².

At what angle does it start to slide?

At the angle whose tangent is μ. For μ = 0.2 that is 11.3°.