Find the time period of the oscillation of mass m in figures 12-E4 a,b,c. What is the equivalent spring constant of the pair of springs in each case ?
(a) Equivalent spring constant,
k=k1+k2 (parallel)
T=2π √mk=2π √mk1+k2
(b) Let us, displace the block m towards left through displacement 'x'.
Resultant force,
F=F1+F2=(k1+k2)x
Acceleration,
(Fm)=(k1+k2)mx
Time period,
T=2π √displacementAcceleration
=2π √xx(k1+k2)m
=2π √mk1+k2
The equivalent spring constant
k=k1+k2
(c) In series connection equivalent spring constant be k.
So, 1k=1k1+1k2=k2+k+1k1k2
⇒ K=k1k2k1+k2
T=2π √mk
=2π √m(k1+k2)k1k2