The average residential home has anywhere from 120 to 250 feet of rain gutters, depending on the number of stories and the amount of roof line. Expect to pay around $3-$5 a lineal foot to have someone install vinyl (PVC) gutters, or about $360-$600 for 120 feet and $750-$1,250 for 250 feet. Vinyl gutters are a fairly simple do-it-yourself project; material alone run about $50-$100 for 120 feet and $90-$180 for 250 feet.
irradiation. n. 1. (General Physics) the act or process of irradiating or the state of being irradiated.2. (General Physics) the apparent enlargement of a brightly lit object when it is viewed against a dark background.3. a shaft of light; beam or ray. 4. (Medicine) med.rÂ·raÂ·diÂ·aÂ·tion. n. 1. The act of exposing or the condition of being exposed to radiation. 2. The use or application of ionizing radiation, especially in medical treatment and for the sterilization or preservation of food.
up vote 5 down vote. The light intensity $I$ is the power $P$, that irradiates an area $A$, $I=P/A$, therefore the units $\mathrm{W}\mathrm{m}^{-2}$. This means, that if you have two beams with equal intensities, the area is the same and the power has to be the same as well.You are probably confused by the relation between frequency and energy of a photon, $E_\nu = h\nu$. But this says just, what the energy of a single photon is.s @daaxix says, you have used intensity to mean irradiance. Irradiance is the amount of power the wave has delivered per unit area and hence, $W/m^2$. Both are quite similar in their definitions. Or in other words, the amplitude of the wave determines the irradiance.