For a sphere in a viscous fluid, terminal velocity is proportional to r2: vt∝r2.
For two balls of the same material in the same fluid: vt2vt1=r22r12.
Given r1=6 mm, vt1=20 cm/s, and r2=3 mm: vt220=936=4.
Therefore, vt2=5 cm/s.
JEE Main 2026 — Physics Mechanics
The terminal velocity of a metallic ball of radius 6 mm in a viscous fluid is 20 cm/s. The terminal velocity of another ball of same material and having radius 3 mm in the same fluid will be ____ cm/s.
Held on 21 Jan 2026 · Verified 6 Jul 2026.
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