1
JEE Main 2021 (Online) 24th February Evening Shift
Numerical
+4
-1
A uniform thin bar of mass 6 kg and length 2.4 meter is bent to make an equilateral hexagon. The moment of inertia about an axis passing through the centre of mass and perpendicular to the plane of hexagon is _______ $$\times$$ 10$$-$$1 kg m2.
2
JEE Main 2020 (Online) 5th September Evening Slot
Numerical
+4
-0
A thin rod of mass 0.9 kg and length 1 m is suspended, at rest, from one end so that it can freely oscillate in the vertical plane. A particle of move 0.1 kg moving in a straight line with velocity 80 m/s hits the rod at its bottom most point and sticks to it (see figure). The angular speed (in rad/s) of the rod immediately after the collision will be _________.
3
JEE Main 2020 (Online) 5th September Morning Slot
Numerical
+4
-0
A force $$\overrightarrow F = \left( {\widehat i + 2\widehat j + 3\widehat k} \right)$$ N acts at a point
$$\left( {4\widehat i + 3\widehat j - \widehat k} \right)$$ m. Then the magnitude of torque
about the point $$\left( {\widehat i + 2\widehat j + \widehat k} \right)$$ m will be $$\sqrt x$$ N m.
The value of x is _______.
4
JEE Main 2020 (Online) 4th September Morning Slot
Numerical
+4
-0
A circular disc of mass M and radius R is rotating about its axis with angular speed $${\omega _1}$$ . If another stationary disc having radius $${R \over 2}$$ and same mass M is droped co-axially on to the rotating disc. Gradually both discs attain constant angular speed $${\omega _2}$$ the energy lost in the process is p% of the initial energy. Value of p is __________.