The period of S. H.M. of a particle is 16 second. The phase difference between the positions at $\mathrm{t}=2 \mathrm{~s}$ and $\mathrm{t}=4 \mathrm{~s}$ will be

A body cools from $60^{\circ} \mathrm{C}$ to $40^{\circ} \mathrm{C}$ in 6 minutes. After next 6 minutes its temperature will be (Temperature of the surroundings is $10^{\circ} \mathrm{C}$ )

A parallel beam of light is incident normally on a plane surface absorbing $50 \%$ of the light and reflecting the rest. If the incident beam carries 90 W of power, the force exerted by it on the surface is ( $\mathrm{C}=$ velocity of light in air $=3 \times 10^8 \mathrm{~m} / \mathrm{s}$ )

A tyre of a vehicle is filled with air having pressure 270 kPa at $27^{\circ} \mathrm{C}$. The air pressure in the tyre when the temperature increases to $37^{\circ} \mathrm{C}$ is