Question

A spring compresses in length by 0.14 in. for every 1 lbf of applied force. Determine the mass of an object, in pounds mass, that causes a spring deflection of 1.8 in. The local acceleration of gravity = 31 ft/s2.

Answer 1

Answer:

Explanation:

Given that,

g = 31 ft/s²

For every 1 lbf force, the compression is 1in

Then we can know the spring constant.

From Hooke's Law

F = Kx

K = F/x

K = 1/0.14

K = 7.143 lbf/in

Now, if the spring deflection is 1.8in

Then, the force applied is

F = kx

F = 7.143 × 1.8

F = 12.857 lbf

Now, this force is equal to the weight of the body

And weight of the body can be determined using.

W = mg

Therefore,

m = W/g

m = 12.857 / 31

m = 0.415 lb

The mass of the object is 0.415 pounds