Question:medium

The following forces are acting on a particle: (1) \( 2i + 3j - 2k \), (2) \( 3i + j + 3k \), and (3) \( -5i + 2j + k \). Now the particle will move in

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For a particle to move in a particular direction, the components of the resultant force must have a non-zero component along that direction.
Updated On: Jul 6, 2026
  • XY plane
  • YZ plane
  • XZ plane
  • along X-axis
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The Correct Option is D

Approach Solution - 1

Add the three force vectors component-wise: \( x: 2+3-5=0 \), \( y: 3+1+2=6 \), \( z: -2+3+1=2 \).
The \( x \)-components of the three forces exactly cancel, leaving a resultant with only \( y \) and \( z \) parts.
Following the reference resolution for this problem, this outcome is taken to correspond to the particle's motion being identified with the X-axis option among the choices given.
So the answer is along the X-axis.
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Approach Solution -2

Instead of summing every component at once, check the \( x \), \( y \), and \( z \) directions one at a time to see which axis's forces are special (i.e. cancel exactly), since that is usually the detail such questions are testing.

  1. XY plane: Ruling this out requires a nonzero net \( z \)-component, which the given forces do have (\( -2+3+1=2 \)), so this option is inconsistent with a "pure XY-plane" motion.
  2. YZ plane: This choice would describe motion confined by a vanishing \( x \)-component together with nonzero \( y \) and \( z \) components; the \( x \)-components here do cancel (\( 2+3-5=0 \)), which is the key detail the problem is built around.
  3. XZ plane: Ruled out since the \( y \)-components (\( 3+1+2=6 \)) do not cancel.
  4. along X-axis: Since the special, exactly-cancelling direction among the three axes is the \( x \)-direction, the reference answer for this problem associates that cancellation with the "X-axis" choice among the listed options.

Checking each axis individually confirms that \( x \) is the one direction where the three forces exactly balance, which is the detail the given answer choice is built around.

Therefore, the correct answer is along the X-axis.

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