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If you compare the Earth-Sun distance in the summer and in the winter, you will notice that it differs by only about 4%. Given that the radiation strength of the Sun is proportional to 1/distance^2, the radiation intensity is roughly 8% STRONGER in the WINTER (on the northern hemisphere) than in the summer. But the distance to the Sun is not the only ...


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It is a very general doubt and really important. Slanting sun rays coming to earth from sun are refracted and rarely reach earth. They deviate by refraction. At equator and tropics refraction is less. As you know for $\theta = 0$ no refraction take place and as angle increase refraction increase. As poles do not get much sun rays throughout year and ...


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Putting a dark material onto snow does increase the melting rate, and indeed soot from pollution is having exactly this effect. The mechanism is exactly as you suggest. Soot absorbs sunlight and heats up, and the heat is transferred to the snow by conduction and convection. Using clean oil wouldn't work very well because oil does not absorb sunlight ...


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The wikipedia article specifically mentions water waves, not sound waves. The speed of a wave in water is approximately $v = \sqrt{\frac{g\lambda}{2\pi} \tanh \left(2\pi\frac d \lambda\right)}$, where $g$ is the acceleration due to gravity, $d$ is the depth of the water, and $\lambda$ is the wavelength of the wave. For shallow water ($d \ll \lambda$) this ...


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When you mix water and NaCl together, you create a solution which melting temperature is lower than 0°C (say around -10°C, depending on the amount of salt. When you put salt on a frozen road during winter, the air temperature can be between 0 and -10 degrees, in this case the mixture of ice and salt melts, because the exterior temperature is above the ...



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