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Two rain drops of radii are in the ratio 1:2, then ratio of their terminal velocities is

Correct answer: D. 1:4

  • A. 1:2
  • B. 2:1
  • C. 4:1
  • D. 1:4

Explanation

Terminal velocity of a spherical object falling through a fluid is proportional to the square of its radius. Therefore, if the radii of two raindrops are in the ratio 1:2, their terminal velocities will be proportional to the square of these radii: (1^2):(2^2) = 1:4. This means the terminal velocity of the smaller raindrop is one-fourth that of the larger one. Other options are incorrect as they do not correctly apply this squared relationship.

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About Fluid Dynamics

Fluid flow is described through speed, pressure and density, including steady flow and the equation of continuity for conserving mass. Bernoulli's equation relates pressure, speed and height, while fluid drag and terminal velocity explain why a falling object eventually moves at constant speed when drag balances its weight.

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