Mkazo wa Mkazo Moduli ya Young - Matatizo na Suluhisho
1. A nylon string has a diameter of 2 mm, pulled by a force of 100 N. Determine the stress!
Inajulikana:
Nguvu (F) = 100 N
Diameter (d) = 2 mm = 0.002 m
Radius (r) = 1 mm = 0.001 m
Inayohitajika: Dhiki
Suluhisho:
Eneo:
A = π r2
A = (3.14)(0.001 m)2 = 0.00000314 m2
A = 3.14 x 10-6 m2
The stress :

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!
Inajulikana:
Original length (l0) = 100 cm = 1 m
The change in length (Δl) = 2 mm = 0.002 m
Inayohitajika: The strain
Suluhisho:
Strain :

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
Inajulikana:
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 = 12.56x10-6 m2
Nguvu (F) = 200 N
Original length of spring (l0) = mita 2
The change in length (Δl) = 2.02 – 2 = 0.02 m
Inayohitajika: (a) The stress (b) The strain c) Young’s modulus
Suluhisho:
(a) The stress

(b) The Strain

(C) Moduli ya vijana

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
Inajulikana:
Young’s modulus (E) = 5 x 109 N / m2
Original length (l0) = mita 2
Nguvu (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 = 7.85x10-5 m2
Alitaka : The change in length (Δl)
Suluhisho:
Young’s modulus formula :
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Mabadiliko ya urefu :

5. A concrete has a height of 5 meters and has unit area of 3 m3 inasaidia a molekuli of 30,000 kg. Determine (a) The stress (b) The strain (c) The change in height! Kuongeza kasi kwa sababu ya mvuto (g) = 10 m/s2. Young’s modulus of concrete = 20 x 109 N / m2
Inajulikana:
Young’s modulus of concrete = 20 x 109 N / m2
Initial height (l0) = mita 5
Unit area (A) = 3 m2
uzito (w) = mg = (30,000)(10) = 300,000 N
Inayohitajika: (a) The stress (b) The strain (c) The change in height!
Suluhisho:
(a) The stress

(b) The Strain

(c) The change in height
