I got the following problem wrong, and don't know why, so hopefully somebody would be able to help me out! Three identical (massless) springs are hung from the ceiling. Spring 1: Nothing hung from spring. The spring's bottom is 0.2 m below the ceiling. Spring 2: A 7 N object is hung from the spring. The spring's bottom is 0.5 m below the ceiling. Spring 3: An object of unknown weight is hung from the spring. The spring's bottom is 1 m below the ceiling. a. Find the spring constant that each spring has. b. Find the weight of the unknown object. For A, I used k = 4pi^2(0.7143)/1. I got 0.7143 as my mass by using F=ma, and I used 1 for T, since no time or frequency was given for either of the 3 springs. I guess since part A was wrong, that answer led to my answer for part B to be wrong also.