The sum of moments of all the particles in a system about its centre of mass is always
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 due to different speeds.
A spring is stretched by 0.40 m when a mass of 0.6 kg is suspended from it. The period of oscillations of the spring loaded by 255 g and put to oscillations is close to (g = 10 ms$$^{-2}$$)
A heavy brass sphere is hung from a spring and it executes vertical vibrations with period T. The sphere is now immersed in a non-viscous liquid with a density (1/10 )th that of brass. When set into vertical vibrations with the sphere remaining inside liquid all the time, the time period will be