Answer:
<u>0.04 °C⁻¹</u>
Explanation:
First, we need to calculate linear expansivity, then after finding that value, we can move on to finding the area expansivity.
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Finding Linear Expansivity :
⇒ α = Final length - Original length / (Original length × ΔT)
⇒ α = 9 - 4 / (4 × 70 - 20)
⇒ α = 5 / 5 × 50
⇒ α = <u>0.02</u>
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Finding Area Expansivity :
⇒ Area Expansivity = 2 × Linear Expansivity
⇒ β = 2 × α
⇒ β = 2 × 0.02
⇒ β = <u>0.04 °C⁻¹</u>
We use the work formula to solve for the unknown in the problem. The formula for work is expressed as the product of the net force and the distance traveled by the object. We were given both the force and the distance so we can solve work directly.
Work = 250 N x 50 m = 12500 J
Thus, the answer is C.
Only once hope this helps