Answer:
The copper wire stretches 6.25 cm and the steel wire stretches 3.75 cm.
Explanation:
Young's modulus is defined as:
E = stress / strain
E = (F / A) / (dL / L)
E = (F L) / (A dL)
Solving for dL:
dL = (F L) / (A E)
The wires have the same force, length, and cross-sectional area. So:
dL₁ + dL₂ = (FL/A) (1/E₁ + 1/E₂)
Given that dL₁ + dL₂ = 0.10 m, E₁ = 20×10¹⁰ N/m², and E₂ = 12×10¹⁰ N/m²:
0.10 = (FL/A) (1/(20×10¹⁰) + 1/(12×10¹⁰))
FL/A = 0.75×10¹⁰ N/m
Solving for dL₁ and dL₂:
dL₁ = (FL/A) / E₁
dL₁ = (0.75×10¹⁰ N/m) / (20×10¹⁰ N/m²)
dL₁ = 0.0375 m
dL₂ = (FL/A) / E₂
dL₂ = (0.75×10¹⁰ N/m) / (12×10¹⁰ N/m²)
dL₂ = 0.0625 m
The copper wire stretches 6.25 cm and the steel wire stretches 3.75 cm.
Answer:
Explanation:
Let us calculate the average velocity .
Average velocity = total distance / total time
Time taken to drive first 15 mi
= 15 / 60 = .25 h
Time taken to drive next 15 mi
= 15 / 30 = .5 h
Total time = .25 + .5 = .75 h
Total distance = 30 mi
average speed = 30 / .75
= 40 mi / h
So average speed is 40 mph which is less than given velocity of 45 mph .
Hence if she travels at 45 mph , she will take less time .
Since the 2 points form a triangle with hypothenuse of √5 [ √(1²+2²)],
I guess apply the formula :
with r as √5 and q as 1x10^-6
not sure about this answer tho
draw a diagram first to understand better
