1. The problem statement, all variables and given/known data: The block of mass m1 as shown in the figure (pic attached)is fastened to the spring and the block of mass m2 is placed against it. a)Find the compression of the spring in equilibrium position. b)The blocks are pushed a further distance (2/k)(m1 + m2)g sinθ against the spring and released. Find the position where the two blocks seperate. 2. Relevant equations: F=kx (Hookes law) 3. The attempt at a solution: a)For the time being...we are replacing the two blocks with a block of equivalent mass(M) i.e M = m1 + m2. At equilibrium, net force on this new block = 0. MgSinθ= kx ⇒x=MgSinθ/k = (m1 + m2)gSinθ/k b) The blocks seperate when normal force between them is zero. So m2gSinθ stops acting on m1 Let the stretch in the spring be y at this instant. So, At this instant, on m2, no N is acting. So, m2a=m2gSinθ ⇒a=gSinθ ⇒Fs/(m1+m2)=gSinθ ⇒ky = (m1+m2)gSinθ ⇒y=(m1+m2)gSinθ/k so, the spring should by stretch by (m1+m2)gSinθ/k Why is the answer given "when the spring attains its normal length".....? where am I going wrong?