The distance that a spring will stretch varies directly as the force applied to the spring. a force of 12 pounds is needed to stretch a spring 9 inches. what force is required to stretch the spring 15 inches?

Force required, F = 20 pounds

Step-by-step explanation:

We have given,

force needed to stretch a spring , F = 12 pounds

Stretched length, x = 9 inches

Since, spring force formula can be given as: F = kx

i.e 12 = k · 9

or k = = 4/3

Now we need to find force for the stretch length = 15 inches

i.e F = kx   , here x =15inches , k = 4/3 and F= ?

or F = (4/3) · 15

or F = 20 pounds

Hence force required, F= 20 pounds

slope is 35 and 20 miles is the y-intercept.

step-by-step explanation:

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like: