Hank is pulling his brother, Benji, on a sled with constant velocity across horizontal ground. The rope attached to the sled makes a 57° angle with the ground. If Hank pulls the rope with 500 N of force, and the combined mass of Benji and the sled is 42 kg, how much normal (support) force does the ground exert on the sled?

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explanation:

their crystal patterns have been disrupted by stress

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.