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
Correct Answer: Option A
Explanation
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 )