Exams › NEET › Physics

A stone of mass 1 kg is tied to a string of length \(\frac{10}{3}\) m and rotated in a vertical circle. If the ratio of maximum tension to minimum tension in the string is 4, the speed of the stone at the highest point of the circular path is: \((g = 10\,\text{m/s}^2)\)

1. 20 m/s
2. 10\sqrt{3} m/s
3. 5\sqrt{2} m/s
4. 10 m/s

Correct answer: 10 m/s

Solution

In vertical circular motion, tension is maximum at the bottom and minimum at the top. Using \(T_b - T_t = 2mg\) and the given ratio \(T_b/T_t = 4\), we get the tension values and then use the top-point equation \(T_t + mg = mv^2/r\).

Related NEET Physics questions

• A stone tied to a string of length 80 cm is whirled in a horizontal circle at constant speed, completing 14 revolutions in 25 s. What is the magnitude of the centripetal acceleration of the stone?
• A coin on a rotating turntable begins to slip when placed 4 cm from the center. If the turntable's angular speed is doubled, at what distance from the center will the coin just start to slip?
• The angular displacement of a rotating body is described by $\theta(t) = \omega_0 t + \frac{1}{2}\alpha t^2$, where $\omega_0 = 1\ \text{rad/s}$ and $\alpha = 1.5\ \text{rad/s}^2$. What is the angular velocity of the body at $t = 2\ \text{s}$?
• A coin rests on a gramophone record rotating at angular velocity \(\omega\). The coefficient of static friction is \(\mu\). The coin rotates without slipping if its distance \(r\) from the center satisfies:
• Two racing cars of masses \(m_1\) and \(m_2\) travel in circles of radii \(r_1\) and \(r_2\), respectively. Both complete one full revolution in the same time period \(t\). What is the ratio of the angular speed of the first car to the second car?
• A wheel starts from rest and undergoes uniform angular acceleration, reaching an angular velocity of 80 rad/s after 5 seconds. What is the total angular displacement of the wheel during this time?

⚔️ Practice NEET Physics free + battle 1v1 →