# Stress, Strain, Tension, Compression, Elasticity ANSWER ALL ...

Urban and Civil

Nov 29, 2013 (4 years and 6 months ago)

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Stress, Strain, Tension, Compression, Elasticity
ANSWER ALL QUESTION ON A SEPARATE SHEET OF PAPER 4 COLUMN FORMAT

2
2
Force
of elasticity =
Strain Area
change in dimension
= Degree of Deformation =
orginal dimension
in Pa (unit of Pressure) 1 Pa = 1 N/m
Area = r = (
Stress
Modulus Stress
Strain
Measured
π π
=
2
D
) **** You NEED THIS FOR #2 and #4
2

1. The heels on a pair of women’s shoes have a radius of .5 cm at the bottom. If 30% of the weight of a woman 480N is
supported by each heel, find the stress on each heel. Stress = Force/area

2. Find the diameter of an 18 m(L) long steel wire that will stretch no more than .009 m(ΔL) when a load (stress) of 3800
N is hung on the end of the wire. The Young’s Modulus for steel wire is 200 x 10
9
N/m
2
.
Stress

Strain
F L
Y
A
L

= =
• Δ

3. For safety in climbing mountaineers use a nylon rope that is 50 m long(L) and .01 m in diameter. When supporting a
900 N climber the rope stretches 1.6 m (ΔL) under tension. Find the Young’s Modulus(Y) for the nylon rope
Stress

Strain
F L
Y
A
L

= =
• Δ

Stress, Strain, Tension, Compression, Elasticity
ANSWER ALL QUESTION ON A SEPARATE SHEET OF PAPER 4 COLUMN FORMAT

4. The elastic limit of steel is 5.0 Pa (N/m
2
), find the minimum diameter a steel wire can to support a 700 N weight
without exceeding its elastic limit.
Force
Maximum Stress =
Minimum Area

5. The distortion of the earth’s crust is an example of sheer on a large scale. A particular rock has a sheer modulus of 1.5
x10
10
Pa(N/m
2
)(Shear Modulus, S). What shear stress is applied when a 10 km layer (h) of rock is sheared a distance
of 5 m (Δx).

6. Human bone has a Young’s Modulus of 14.5 x10
8
N/m
2
(Y). Under compression, it can withstand a stress of about 160
x 10
6
N/m
2
(stress) before breaking. Assuming a human adult thigh bone (femur) is about .5 m (L) long, how much
compression (ΔL) can the bone withstand before breaking.
F
F L
A
Y
L
A
L
L

= =
Δ
•Δ

Strain
F
Shear Stress F h
A
S
x
Shear A x
h

= = =
Δ
• Δ
Stress, Strain, Tension, Compression, Elasticity
ANSWER ALL QUESTION ON A SEPARATE SHEET OF PAPER 4 COLUMN FORMAT

7. A cylindrical aluminum pillar 7.00 high has a radius of 30.0 cm. If a 2000-kg sculpture is placed on top of the pillar,
by how much is the pillar compressed?

8. A mass of 2.00 kg is supported by a copper wire of length 4.00 m and diameter 4.00 mm. Determine (a) the stress in
the wire and (b) the elongation of the wire.

9. A uniform pressure of 5.00 × 10
4
Pa is exerted on a copper block having a volume of 10
–3
m
3
. What is the change in
volume of the block?

10. During a tensile strength experiment, a small-diameter fiber is elongated by a force of 0.0250 N. The fiber has an
initial length of 0.200 m and stretches a distance of 4.00 × 10
24
m. The Young’s modulus for the material being tested
is 7.60 × 10
10
Pa. Determine the diameter of the fiber.