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Classical Mechanics FAQ

Work done against gravity lifting a 2 kg mass 5 m is:

98 J. W = mgh = 2×9.8×5 = 98 J.

Short Answer

98 J is the best answer.

This concept lives inside the mechanics toolkit: forces, motion, energy, momentum, and rotation. The safest way to solve it is to name the governing law first, then connect the variables in units you trust.

W = mgh = 2×9.8×5 = 98 J.

Why This Answer Is Correct

This is a Medium-level question in Classical Mechanics. The prompt is really testing whether you can connect the concept to its defining physical relationship instead of picking a nearby-but-wrong term.

Mechanics questions usually become easier once you identify whether the problem is about force balance, kinematics, energy, or conservation.

Choices At A Glance

  • A. 10 J
  • B. 98 J
  • C. 98 W
  • D. 49 J

When similar options appear on an exam, eliminate the ones that break the core law, use the wrong units, or confuse a definition with a consequence.

Topic Snapshot

Topic: Classical Mechanics

Difficulty: Medium

Best next move: Re-state the governing law in your own words, then solve one more example from the same topic before moving on.