The device shown is used as an accelerometer and consists of a 4.8-oz plunger A
ID: 1374703 • Letter: T
Question
The device shown is used as an accelerometer and consists of a 4.8-oz plunger A which deflects the spring as the housing of the unit is given an upward acceleration a. Specify the necessary spring stiffness k which will permit the plunger to deflect 0.22 in. beyond the equilibrium position and touch the electrical contact when the steadily but slowly increasing upward acceleration reaches 3.7g. Friction may be neglected.
The device shown is used as an accelerometer and consists of a 4.8-oz plunger A which deflects the spring as the housing of the unit is given an upward acceleration a. Specify the necessary spring stiffness k which will permit the plunger to deflect 0.22 in. beyond the equilibrium position and touch the electrical contact when the steadily but slowly increasing upward acceleration reaches 3.7g. Friction may be neglected.Explanation / Answer
m=4.8oz=0.13kg
x=0.22inch=0.0055m
From spring force and Newton law relationship
ma=Kx
K=ma /x
= (0.13)(3.7)(10) / 0.0055
=874N/m