Circular Motion

If a stone of mass 0.5 kg tied to one end of a wire is whirled in a circular path of radius 2 m with a speed $40 \mathrm{rev} / \mathrm{min}$ in a horizontal plane, then the tension in the wire is nearly

A wire of length 2.5 m is fixed at one end and a box of mass 4 kg is tied at the other end. If the wire rotates in a horizontal circle about the fixed end with $\frac{2}{\pi}$ rotations per second, then the tension in the wire is

Ratio of angular velocity of hour hand of a watch and the angular velocity of rotation of Earth is

If a particle of mass ' $m$ ' covers half of the horizontal circle with constant speed ' $v$ ', then the change in its kinetic energy is

The centripetal acceleration of a particle in uniform circular motion is $18 \mathrm{~ms}^{-2}$. If the radius of the circular path is 50 cm , the change in velocity of the particle in a time of $\frac{\pi}{18} \mathrm{~s}$ is

A small disc is on the top of a smooth hemisphere of radius $R$. The smallest horizontal velocity $v$ that should be imparted to the disc, so that disc leaves the hemisphere surface without sliding down is ( there is no friction )

A particle revolving in a circular path travels the first half of the circumference in 4 s and the next half in 2 s . What is its average angular velocity?

A wheel of angular speed $600 \mathrm{rev} / \mathrm{min}$ in is made to slow down at a rate of $2 \mathrm{rad} \mathrm{s}^{-2}$. The number of revolutions made by the wheel before coming to rest is

A block of mass $m$ and charge $q$ is connected to a point owith an inextensible string. This system is on a horizontal table. An electric field $E$ is applied perpendicular to the string and in the plane of the horizontal table. The tensio...

A body of mass 10 kg is attached to a wire of 0.3 m length. The breaking stress is 4.8 \(\times\) 10\(^7\) Nm\(^{-2}\). The area of cross-section from the wire is 10\(^{-6}\) m\(^{2}\). The maximum angular velocity with which it can be rota...

Assertion (A) Two identical trains move in
opposite senses in equatorial plane with
same speeds relative to the Earth’s surface.
They have equal magnitude of normal
reaction.
Reason (R) The trains have different
centripetal accelerations du...

A motor cyclist wants to drive in horizontal circles on the vertical inner surface of a large cylindrical wooden well of radius \(8.0 \mathrm{~m}\), with minimum speed of \(5 \sqrt{5} \mathrm{~ms}^{-1}\). The minimum value of coefficient of...

A 500 kg car takes a round turn of radius
50 m with a velocity of 36 km/h. The
centripetal force acting on the car is