Two bodies of masses 1 kg and 4 kg are connected to a vertical spring , as shown in the figure . The smaller mass executes simple harmonic motion of angular frequency 25 rad/s , and amplitude 1.6 cm while the bigger mass remains stationary on the ground . The maximum force exerted by the system on the floor is (take g=$\;10 ms^{-2}$) .

Question

$(a)\;20\;N\qquad(b)\;10\;N\qquad(c)\;60\;N\qquad(d)\;40\;N$