The distance (d) that a spring will stretch varies directly as the force (f) applied to the spring. If a force of 4 lb is required to stretch a spring 2 in., what force is required to stretch the spring 6 in.?
A) 1 lb
B) 3 lb
C) 12 lb
D) 15 lb
E) 13 lb

Question

Quizplus · Accepted Answer

We can use the formula for direct variation:

d = kf

where k is a proportionality constant.

To solve for k, we can use the given values:

2 = 4k

k = 1/2

Now we can use the formula to find the force (f) required to stretch the spring 6 in:

6 = (1/2)f

f = 12

Therefore, the force required to stretch the spring 6 in. is 12 lb, which corresponds to choice C.

The Distance (D) That a Spring Will Stretch Varies Directly