A mass M attached to a spring has period 1 s. Adding 3 kg increases its period to 2 s. Find M (kg).
Physics · Mixed Chapter
JEE Main Practice

Question

A mass M attached to a spring has period 1 s. Adding 3 kg increases its period to 2 s. Find M (kg).

G1 Physics · Accepted Answer

Step 1: Spring time period T=2π√(M/k), hence T² ∝M. Step 2: (T₂/T₁)² = (M+3)/M = (2/1)²=4. Step 3: M+3=4M ⇒M=1 kg.