1. The problem statement, all variables and given/known data Hello, two basic questions on the same topic and I think the book answer is wrong so I've posted both here if that's okay. Q1. What force is required to stretch a spring with spring constant 0.2 N/cm a distance of 5 cm? Q2. A vertical spring stretches 5 cm under a load of 100 g. Determine the spring constant. 2. Relevant equations F = kx k = spring contant x = extension in spring 3. The attempt at a solution Q1. F = kx F = 0.2 x 5 F = 1 N 1 Newton is my answer but the book says 0.01 N. Q2. 100g = 0.1kg therefore weight (force) = 0.1 x 10 = 1 N F = kx 1 = 5k k = 0.2 N/cm 0.2 N/cm is my answer but the book says 0.05 N/cm. I can't see where I've gone wrong. Please advise.