Frequency of a Car's Vibrations???? 1. The problem statement, all variables and given/known data When four people with a combined mass of 297 kg sit down in a car, they find that the car drops 2.8 cm lower on its springs. Then they get out of the car and bounce it up and down. What is the frequency of the car's vibration if its empty mass is 2210 kg 2. Relevant equations F = kx x=k/F f=(1/2)(pi)sqrt(m/k) F=mg 3. The attempt at a solution I tried using F=mg=(297)(9.8) =2910.6 N k=103,950 N/m f=(1/2)(pi)sqrt(2210/103950)=0.229 which was the wrong answer. Not really sure what i'm doing wrong. Please provide solution and approach to problem. Thanks!!