O rază de lumină cade sub un unghi de incidență i=30⁰ pe o suprafață
plană ce separă două materiale transparente cu indici de refracție n 1 = 1,60
și n 2 = 1,40.
Calculați unghiul de refracție (din mediul cu indicele de refracție mai mic).
Sugestie: sin 30⁰ = ½.

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Afeather of mass 0.001 kg falls from a height of 2 m. under realistic conditions, it experiences air resistance. based on what you know about friction, what can you say about the kinetic energy of the feather as it reaches the ground? acceleration due to gravity is g = 9.8 m/s2. a. ke < 0.0196 j b. ke = 00196 j c. je = 0 j d. ke > 0.0196 j

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