A ball is thrown into the air with certain velocity v making an angle with horizontal. If air resistance is neglected, then at maximum height its velocity is:

  • A. Equal to initial velocity
  • B. Half of initial velocity
  • C. Equal to zero
  • D. Minimum but not zero

Explanation

At the top the vertical component has fallen to zero, but the horizontal component is unchanged throughout the flight because no horizontal force acts, so the ball still moves horizontally at v cos theta. The speed is therefore at its minimum for the flight yet not zero, which is the distinction being tested. Only a ball thrown straight up would momentarily stop.

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