A construction worker runs a jack hammer for 1.5 hours. The jack hammer has 2.4 kilowatts of power. How much electrical energy d
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Answer:
1) 0.1584 m
2) To allow for expansion without derailment
3) 0.101376 m
4) 213.675 °C
5) 266.67 m
6) 8.33 × 10⁻⁶ /°C
7) The alloy meets the requirement
8) 1.95 × 10⁻³ /°C
9) 32.095 m
10) -12157.72°C
Explanation:
1) Equation for the coefficient of linear expansion =
Where:
ΔL = Change in length = Required
L = Initial length = 1.32 × 10⁴ m
= Coefficient of linear expansion of steel = 12 × 10⁻⁶ /°C
ΔT = Change in temperature = 37°C - 27°C = 10°C
Plugging the values in the equation for the temperature expansion of steel, we have m;
ΔL = L × ×ΔT = 1.32 × 10⁴ × 12 × 10⁻⁶ × 10 = 0.1584 m
2. Here we have that by segmenting railroad tracks into short pieces, the expansion of the metal tracks with temperature can be absorbed by the gaps between the segment without distorting the shape and direction (pattern) of the tracks
3. Here we have;
= Coefficient of linear expansion of iron = 12 × 10⁻⁶ /°C
ΔT = Temperature change = 27°C - 3°C = 24°C
L = Height of the Eiffel Tower = 352 meters
∴ ΔL = L × ×ΔT = 352 × 12 × 10⁻⁶ × 24 = 0.101376 m
Therefore, the height of the Eiffel Tower changes from 352 m to about 352.101376 m each year, with an average change in height experienced each year = 0.101376 m
4. Here, we have
L = 13.0 ft
ΔL = 1 in.
= 30 × 10⁻⁶ /°C
ΔT = Required temperature change
From
5. Here, we have;
∴ L = 1/(150×25 × 10⁻⁶) = 266.67 m
The bars original length = 266.67 m
6. Here we have;
Where:
ΔL = 3.00 - 3.002 = 0.002 m
L = 3.00 m
ΔT = 110°C - 30°C = 80°C
∴ = 0.002/(3.00 × 80) = 8.33 × 10⁻⁶ /°C
7. Here we have;
ΔL = L × ×ΔT = 3 × 8.33 × 10⁻⁶ × 210 = 0.00525 m
Therefore, final length = 3.00 m + 0.00525 m = 3.00525 m
Since 3.00525 m < 3.017 m hence the alloy meets the requirement.
8. Here, we have
L = 3.2 m
ΔL = 0.5 m
ΔT = 84°C - 24°C = 60°C
∴ = 0.5/(3.2 × 60) = 1.95 × 10⁻³ /°C
The coefficient of linear expansion of the material from which the rod is made = 1.95 × 10⁻³ /°C
9. Here, we have
Length of steel girder, L = 32.10 m
ΔT = 8°C - 22°C = -14°C
= 12 × 10⁻⁶ /°C
ΔL = L × ×ΔT
Hence ΔL = 32.1 × 12 × 10⁻⁶× -14 = -0.0054 m
New length = 32.1 - 0.0054 = 32.095 m
10. Here we have;
ΔL = 92.6 cm - 123 cm = -30.4 cm
= 2.0 × 10⁻⁵ /°C
L = 123 cm
∴
Therefore, the temperature will be 200 - 12357.724 = -12157.72°C.