Two identical springs with spring constant 50 N/m support a 5.0 N weight as in the picture below.What is the tension in spring A?
A)1.45 N
B)2.50 N
C)2.89 N
D)3.75 N
E)5.00 N

Question

Two identical springs with spring constant 50 N/m support a 5.0 N weight as in the picture below.What is the tension in spring A? 
A)1.45 N 
B)2.50 N 
C)2.89 N 
D)3.75 N 
E)5.00 N

Quizplus · Accepted Answer

Since the weight is evenly distributed between the two identical springs, each spring has to support half of the weight, which is 2.5 N. 
Using Hooke's Law, F = kx, we can find the amount that spring A stretches: 
2.5 N = (50 N/m)x 
x = 0.05 m 
The tension in spring A is the force required to stretch it by 0.05 m: 
T = kx = (50 N/m)(0.05 m) = 2.50 N 
Therefore, the best choice is C.

Two Identical Springs with Spring Constant 50 N/m Support a 5.0