I need the answer to this question written out in steps please

Question

The distance a spring stretches varies directly with the weight of the object hung on the spring. If a 20 pound weight stretches a spring 8 inches. How far will a 50 pound weight stretch this spring

Answer 1

Amy, not sure why this physics questions shows up under College Algebra, but here's how to do it anyway.

The question is just an application of Hook's Law:

F = kx where k = spring constant and x = distance stretched by the force, F

The force exerted by a weight m = mg where g = gravitational acceleration.

∴ 20g = 8k

=> k = 20g/8 = 5g/2 = 2.5g

For the 50 lb weight, 50g = (2.5g) x

=> x = 50g/2.5g

= 20 cm