(10) Use the intensity of sunlight measured on Earth (I = 1400 W/m²) to estimate the (surface) temperature of the Sun. Light takes about 500 s on average to get from the sun to the earth.

The next four questions use this description.  Our Sun has a peak emission wavelength of about 500 nm and a radius of about 700,000 km. Your dark-adapted eye has a pupil diameter of about 7 mm and can detect light intensity down to about 1.5 x 10-11 W/m2.  Assume the emissivity of the Sun is equal to 1. First, given these numbers, what is the surface temperature of the Sun in Kelvin to 3 significant digits? What is the power output of the Sun in moles of watts?  (in other words, take the number of watts and divide it by Avogadro's number) Assuming that all of the Sun's power is given off as 500 nm photons*, how many photons are given off by the Sun every second? Report your answer to the nearest power of 10 (e.g. if you got 7 x 1024, give your answer as 25).

The temperature of a 5.00-kg lead brick is increased by 525 C°. If the specific heat capacity of lead is 128 J/(kg.C°), what is the increase in the mass of the lead brick when it has reached its final temperature? O 5.80 × 10- -11 kg O 9.12 × 10-11 kg O 1.60 × 10-12 kg O 3.73 × 10-12 kg O 2.80 × 10-12 kg

What is the change in length of a 3.4-cm-long column of mercury if its temperature changes from 35 ºC to 35.3 ºC, assuming the mercury is unconstrained? The thermal coefficient of expansion of mercury is 6×10-5 /oC.

Water with a mass of mW = 0.400 kg and temperature of TW = 15.5°C is poured into an insulated bucket containing mI = 0.19 kg of ice at a temperature of TI = -15°C. Assume the specific heats of ice and water are constant at cI = 2.10×103 J/(kg⋅°C) and cW = 4.19×103 J/(kg⋅°C), respectively. The latent heat of fusion for water is Lf = 334×103 J/kg.  Part (a)  What is the final temperature of the mixture, in degrees Celsius?  Tfinal =         Part (b)  Enter an expression for the mass of ice, in kilograms, that has melted when the mixture reaches its final temperature.  mmelt =     Part (c)  Calculate how much ice, in kilograms, has melted when the mixture reaches its final temperature.  mmelt =