Rotational Dynamics — Physics STD 12 Science — Question

you look at the source through two polarizers and rotate one of them around the path of light for one full rotation?

A particle in S.H.M. has a period of 2 seconds and amplitude of \(10 cm\). Calculate the acceleration when it is at \(4 cm\) from its positive extreme position.

The surface tension of water at \(0^{\circ} C\) is 75.5 dyne \(/ cm\). Find surface tension of water at \(25^{\circ} C\). [a for water \(=0.0021 /{ }^{\circ} C\) ]

A bar magnet of mass \(120 g\) in the form of a rectangular parallelopiped, has dimensions \(l=40 mm\), \(b=10 mm\) and \(h=80 mm\), with its dimension ' \(h\) ' vertical, the magnet performs angular oscillations in the plane of the magnetic field with period \(\pi\) seconds. If the magnetic moment is \(3.4 Am ^2\), determine the influencing magnetic field.

The top of a cloud of smoke holds together for hours. Why?

Draw a neat labelled diagram for Ferry's perfectly black body

Assuming the expression for the kinetic energy of a body rolling on a plane surface without slipping, deduce the expression for the total kinetic energy of rolling motion for
(i) a ring
(ii) a disk
(iii) a hollow sphere. Also, find the ratio of rotational kinetic energy to total kinetic energy for each body.

The threshold wavelength of silver is 3800Å. Calculate the maximum kinetic energy in eV of photoelectrons emitted, when ultraviolet light of wavelength 2600Å falls on it. [Planck's constant, \(h=6.63 \times 10^{-34} J . s\)., Velocity of light in air, \(c=3 \times 10^3 m / s\)