Question

In the figure given below, a block of mass $M=490 g$ placed on a frictionless table is connected with two springs having same spring constant $\left( K =2 N m ^{-1}\right)$ If the block is horizontally displaced through ' $X$ ' $m$ then the number of complete oscillations it will make in $14 \pi$ seconds will be

Answer 1

The correct answer is 20.

Keff =K+K as both springs are in use in parallel
=2k
=2×2=4N/m
m=490gm
=0.49kg
T=2πKeffm​​=2π40.49kg​​
=2π40049​​=2π207​=107π​
No. of oscillation in the 14π is
N=T time ​=7π/1014π​=20