The kinetic energy of a light body and a heavy body is same. Which one of them has greater momentum?

Four electric charges $$+\mathrm{q},+\mathrm{q},-\mathrm{q}$$ and $$-\mathrm{q}$$ are placed in order at the corners of a square of side $$2 \mathrm{~L}$$. The electric potential at point midway between the two positive charges is

White light consists of wavelengths from $$480 \mathrm{~nm}$$ to $$672 \mathrm{~nm}$$. What will be the wavelength range when white light is passed through glass of refractive index 1.6?

A metal sphere cools at the rate of $$1.5^{\circ} \mathrm{C} / \mathrm{min}$$ when its temperature is $$80^{\circ} \mathrm{C}$$. At what rate will it cool when its temperature falls to $$50^{\circ} \mathrm{C}$$. [Temperature of surrounding is $$30^{\circ} \mathrm{C}$$]