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Simple Machines - Wedge

Grade 6ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

A wedge is a simple machine that consists of two inclined planes joined back-to-back to form a sharp or tapering edge.

The primary function of a wedge is to change the direction of the input force. When force is applied to the head (blunt end), it is redirected perpendicular to the slanting surfaces to split or push objects apart.

Common examples of wedges include an axe, a knife, a chisel, a nail, and a wood splitter.

The Mechanical Advantage (MAMA) of a wedge depends on its dimensions: the longer and thinner the wedge, the higher the MAMA, making it easier to cut or split objects.

A wedge can also be used to hold objects in place through friction, such as a doorstop or a shim.

📐Formulae

MechanicalAdvantage(MA)=Length of the sloping surface (L)Thickness of the wedge (t)Mechanical Advantage (MA) = \frac{\text{Length of the sloping surface (L)}}{\text{Thickness of the wedge (t)}}

MA=LtMA = \frac{L}{t}

💡Examples

Problem 1:

A wood-splitting wedge has a length of 25 cm25 \text{ cm} and a thickness at the head of 5 cm5 \text{ cm}. Calculate the Mechanical Advantage (MAMA) of this wedge.

Solution:

Given: Length (LL) = 25 cm25 \text{ cm}, Thickness (tt) = 5 cm5 \text{ cm}. Using the formula: MA=Lt=25 cm5 cm=5MA = \frac{L}{t} = \frac{25 \text{ cm}}{5 \text{ cm}} = 5.

Explanation:

The Mechanical Advantage of the wedge is 55. This means the wedge multiplies the input effort by 55 times to split the wood.

Problem 2:

Which wedge will be more efficient for cutting: Wedge A with a length of 10 cm10 \text{ cm} and thickness 2 cm2 \text{ cm}, or Wedge B with a length of 10 cm10 \text{ cm} and thickness 4 cm4 \text{ cm}?

Solution:

For Wedge A: MAA=102=5MA_A = \frac{10}{2} = 5. For Wedge B: MAB=104=2.5MA_B = \frac{10}{4} = 2.5. Since MAA>MABMA_A > MA_B, Wedge A is more efficient.

Explanation:

A thinner wedge (Wedge A) provides a higher Mechanical Advantage because the angle of the slope is smaller, requiring less effort to move through the material.

Wedge - Revision Notes & Key Formulas | ICSE Class 6 Science