1. A 100-watt lightbulb radiates energy at a rate of 100 J/s(The watt, a unit of power, or energy over time, is defined as 1J/s). If all of the light emitted has a wavelength of 505nm, howmany photons are emitted per second? (Assume three significantfigures in this calculation.)
2.Calculate the de Broglie wavelength of a 143-g baseball travelingat 80 mph .
3.An electron undergoes a transition from an initial(ni) to a final (nf ) energy state. The energiesof the ni and nf energy states are−2.179×10−18 J and −8.720×10−20 J, respectively.
Calculate the wavelength (λ) of the light in nanometers(nm) corresponding to the energy change (ΔE) value of thistransition. You can use the following values for yourcalculations:
Planck′s constant (h)speed of light (c)1m===6.626×10−34 J⋅s2.998×108 m/s109 nm
