Stress Strain Young's modulus - Problems and Solutions

Tegasan, Regangan, Modulus Young – Masalah dan Penyelesaian

1. A nylon string has a diameter of 2 mm, pulled by a force of 100 N. Determine the stress!

Diketahui:

Memaksa (F) = 100 N

Diameter (d) = 2 mm = 0.002 m

Radius (r) = 1 mm = 0.001 m

Dikehendaki: Tekanan

Penyelesaian:

Kawasan :

A = π r²

A = (3.14)(0.001 m)² = 0.00000314 m²

A = 3.14x10^-6 m²

The stress :

Stress, strain, Young's modulus sample problems with solutions 1

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2. A cord has original length of 100 cm is pulled by a force. The change in length of the cord is 2 mm. Determine the strain!

Diketahui:

Original length (l₀) = 100 cm = 1 m

The change in length (Δl) = 2 mm = 0.002 m

Dikehendaki: The strain

Penyelesaian:

Strain :

Stress, strain, Young's modulus sample problems with solutions 2

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3. A string 4 mm in diameter has original length 2 m. The string is pulled by a force of 200 N. If the final length of the spring is 2.02 m, determine : (a) stress (b) strain (c) Young’s modulus

Diketahui:

Diameter (d) = 4 mm = 0.004 m

Radius (r) = 2 mm = 0.002 m

Area (A) = π r² = (3.14)(0.002 m)²

Area (A) = 0.00001256 m²= 12.56 x 10^-6 m²

Daya (F) = 200 N

Original length of spring (l₀) = 2m

The change in length (Δl) = 2.02 – 2 = 0.02 m

Dikehendaki: (a) The stress (b) The strain c) Young’s modulus

Penyelesaian:

(a) The stress

Stress, strain, Young's modulus sample problems with solutions 3

(b) The Strain

Stress, strain, Young's modulus sample problems with solutions 4

Stress, strain, Young's modulus sample problems with solutions 5

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4. A string has a diameter of 1 cm and the original length of 2 m. The string is pulled by a force of 200 N. Determine the change in length of the string! Young’s modulus of the string = 5 x 10⁹ N / m²

Diketahui:

Young’s modulus (E) = 5 x 10⁹ N / m²

Original length (l₀) = 2m

Daya (F) = 200 N

Diameter (d) = 1 cm = 0.01 m

Radius (r) = 0.5 cm = 0.005 m = 5 x 10^-3 m

Area (A) = π r² = (3.14)(5 x 10^-3 m)²= (3.14)(25 x 10^-6 m²)

Area (A) = 78.5 x 10^-6 m²= 7.85 x 10^-5 m²

Dikehendaki : The change in length (Δl)

Penyelesaian:

Young’s modulus formula :

Perubahan panjang :

Stress, strain, Young's modulus sample problems with solutions 7

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5. A concrete has a height of 5 meters and has unit area of 3 m³ menyokong a besar-besaran of 30,000 kg. Determine (a) The stress (b) The strain (c) The change in height! Pecutan kerana graviti (g) = 10 m/s². Young’s modulus of concrete = 20 x 10⁹ N / m²