If a force of 50N stretches a wire from 20m to 20.01m, what is the amount of force required to stretch the same material from 20m to 20.05m?
A
250N
B
200N
C
100N
D
50N
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Original length = 20m
first new length = 20.01m
first increase in length = 20.01m - 20m = 0.01m
Second new length = 20.05m
second increase in length = 20.05 - 20m = 0.05m
From hooke's law = \( \frac{F_1}{e_1} = \frac{F_2}{e_2}\)
\(\implies \frac{50}{0.01} = \frac{F_2}{0.05}\)
\(\implies F_2 = \frac{50 \times 0.05}{0.01} = 250N \)
Source: Official Exam / Past Question Archive