The momentum of a photon is $2 \times 10^{-16} \text{ g} \cdot \text{cm/s}$. Its energy is:

If $5\%$ of the energy supplied to a bulb is irradiated as visible light,how many quanta are emitted per second by a $100 \, W$ lamp? Assume the wavelength of visible light is $5.6 \times 10^{-5} \, cm$.

The energy of a photon of light of wavelength $450 \ nm$ is

An electric bulb of $100 \ W$ power emits photons of wavelength $410 \ nm$ per second. The number of photons emitted per second is: $(h = 6.63 \times 10^{-34} \ J \cdot s, c = 3 \times 10^8 \ m/s)$

$A$ photon,an electron,and a uranium nucleus all have the same wavelength. The one with the most energy is:

Solar energy is incident normally on the earth's surface at the rate of about $1.4 \, kW m^{-2}$. The distance between the earth and the sun is $1.5 \times 10^{11} \, m$. Energy $E$ and mass $m$ are related by Einstein's equation $E = mc^2$,where $c = 3 \times 10^8 \, m s^{-1}$ is the speed of light in free space. The decrease in the mass of the sun is ........... $\, kg s^{-1}$.