Collinear but opposite forces (P > Q) Two forces P and Q act along the same straight line but in opposite directions, with P greater than Q. What is the magnitude of the resultant force?

Introduction / Context:
Resultant of collinear forces is found by algebraic addition with appropriate signs. Here, the forces are opposite in sense along the same line.

Given Data / Assumptions:

• P and Q act along one line.
• P > Q and directions are opposite.
• We seek only the magnitude of the resultant.

Concept / Approach:
Assign a positive direction; take the algebraic sum. If P is chosen positive and Q acts in the negative sense, the resultant R = P − Q. The direction will be that of the larger force, i.e., along P.

Step-by-Step Solution:

Verification / Alternative check:
Vector diagram: two arrows in opposite directions; the smaller cancels part of the larger, leaving difference in the larger’s sense.

Why Other Options Are Wrong:

• P + Q: would apply if both forces acted in the same direction.
• P/Q or Q/P: dimensionally incorrect for a force resultant.

Common Pitfalls:
Confusing magnitude with signed result; here only the magnitude is requested, which is the absolute difference.

Final Answer:
P - Q