Question 82492
the distance a spring stretches is directly proportional to the load (or force) on the spring x=kf


let L equal the unstretched length ... so L+8k=76 ... and L+14k=85


multiplying the first equation by 7/4 and subtracting the second equation gives (7/4)L+14k-(L+14K)=(7/4)76-85


so (3/4)L=48 ... L=64 cm