Visible light of wavelength 6000 $$ \times $$ 10^-8 cm falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at 60^o from the central maximum. If the first minimum is produced at $$\theta $$₁, then $$\theta $$₁, is close to :

A non-isotropic solid metal cube has coefficients of linear expansion as :
5 $$ \times $$ 10^-5/^oC along the x-axis and 5 $$ \times $$ 10^-6/^oC along the y and the z-axis. If the coefficient of volume expansion of the solid is C $$ \times $$ 10^-6/^oC then the value of C is

Three point particles of masses 1.0 kg, 1.5 kg and 2.5 kg are placed at three corners of a right angle triangle of sides 4.0 cm, 3.0 cm and 5.0 cm as shown in the figure. The center of mass of the system is at a point: