Question

The distance a spring stretches varies directly as the amount of weight that is hanging on it. A weight of 2.5 pounds stretches a spring 18 inches. Find the stretch of the spring when a weight of 6.4 pounds is hanging on it.

Answer 1

We use the equation y = kx
y = 18, x = 2.5

18 = k2.5
k = 7.2

x = 6.4
y = 7.2*6.4
y = 46.08

hope this help

Answer 2

Answer:

The stretch of the spring is 46.08 inches.

Explanation:

Given that,

Weight = 2.5 pounds

Stretches a spring = 18 inches

new weight = 6.4

We need to calculate the stretch of the spring

let stretch of the spring is x .

Using formula of restoring force

$F=-kx$

For first weight,

$2.5=k\times18$....(I)

For another weight,

$6.4=k\times x$....(II)

Ratio of equation (I) and (II)

$\dfrac{2.5}{6.4}=\dfrac{18}{x}$

$x=\dfrac{18\times6.4}{2.5}$

$x = 46.08\ inches$

Hence, The stretch of the spring is 46.08 inches.