The amount a spring will stretch S is proportional to the force (or weight) F attached to the spring . If a spring stretches 8.9 inches when 20 pounds are attached how far will it stretch when 70 pounds are attached?
A:3.54 inches
B:2.54 inches
C:31.15 inches
D:30.15 inches
Can someone help me this is the only one I'm not sure about.
(70/20) * 8.9
Thank You
Go from here.
To solve this problem, we need to use the concept of proportionality between the force and the amount of stretch in the spring.
Let's denote the stretch of the spring as S and the force attached to the spring as F. We are given that S is directly proportional to F, which means we can write this relationship as:
S = kF
where k is the constant of proportionality.
We are also given that when 20 pounds are attached to the spring, it stretches 8.9 inches. Substituting these values into the equation, we get:
8.9 = k(20)
Solving for k, we divide both sides of the equation by 20:
k = 8.9 / 20
k = 0.445
Now that we have the value of k, we can use it to find the stretch of the spring when 70 pounds are attached. Substituting F = 70 into the equation, we get:
S = 0.445(70)
S = 31.15
Therefore, the spring will stretch 31.15 inches when 70 pounds are attached.
So, the correct answer is C: 31.15 inches.