A bob is whirled in a horizontal plane by means of a string with an initial speed of ω rpm. The tension in the string is T. If speed becomes 2ω while keeping the same radius, the tension in the string becomes: (a) T (b) 4T (c) T/4 (d) √(2)T

Answer: (b). Tension provides the centripetal force: T = mω² r. Same r, ω → 2ω: T' = m(2ω)² r = 4T So the answer is (b) 4T.

A bob is whirled in a horizontal plane by means of a string with an… | NEET 2024

Q22NEET 2024Easy

Rotational Kinematics & Dynamics

A bob is whirled in a horizontal plane by means of a string with an initial speed of $\omega\text{ rpm}$ . The tension in the string is $T$ . If speed becomes $2\omega$ while keeping the same radius, the tension in the string becomes:

Show answer and solution

Answer: (b)

Tension provides the centripetal force: $T = m\omega^2 r$ .
Same $r$ , $\omega \to 2\omega$ : $T' = m(2\omega)^2 r = 4T$
So the answer is (b) $4T$ .

Report a mistake

Rotational Kinematics & Dynamics question from NEET 2024

More questions on Rotational Kinematics & Dynamics