The block of mass m1 shown in figure (12-E2) is fastened to the spring and the block of mass m2 is placed against it. (a) Find the compression of the spring in the equilibrium position. (b) The blocks are pushed a further distance (2/k) (m1+m2)g sin θ against the spring and released. Find the position where the two blocks separate. (c) What is the common speed of blocks at the time of separation ?
(a) At the equilibrium condition,
kx=(m1+m2) g sin θ
⇒ x=(m1+m2) g sin θk
(b) x1=2k(m1+m2) g sin θ (Given)
when the system is released, it will start to make SHM.
where, ω=√km1+m2
when the blocks lose contact,
p=0
So, m2g sin θ=m2x2×km1+m2
⇒ x2=(m1+m2) g sin θk
So the blocks will lose contact with each other when the springs attain its natural length.
(c) Let the common speed attained by both the blocks be v.
12(m1+M2)v2−0
=12k(x1+x2)2−)(m1+m2) g sin θ (x+x1)
[x+x1= total compression ]
⇒ 12(m1+m2)v2
=12k(3k)(m1+m2) g sin θ−(m1+m2) g sin θ−(x1+x2)
⇒ 12(m1+m2)v2=12(m1+m2) g sin θ×(3k)(m1+m2) sin θ
⇒ v=√{3k(m1+m2)} g sin θ