Two identical blocks P and Q have mass ‘m’ each. They are attached to two identical springs initially unstretched. Now the left spring (along with P) is compressed by A2 and the right spring (along with Q) is compressed by A. Both the blocks are released simultaneously. They collide perfectly inelastically. Initial time period of both the blocks was T. [consider k as spring constant of each spring]
The time period and amplitude of oscillation of the combined mass is respectively,
T and A4
Time Period:
They will collide at their mean positions because time period of both are same and that is 2π√mk. After collision combined mass is 2m and keff=2k. Hence, time period remains unchanged.
Amplitude:
Applying conservation of linear momentum, velocity of combined mass just after collision is v=Aω4
Since this is the velocity at mean position,
Hence, v=ω′A′
or ωA4=ω′A′
or A′=A4asω′=ω=√km=√2k2m