mMCQ.

Navigation Menu

Step into mMCQ.

Launch mMCQ. diagnostic

Explore mMCQ.

MDCAT prepFree DiagnosticPricing & SubscribeSign in

Resources

Terms & Conditions

mMCQ.

© 2021 - 2025 mMCQ.All rights reserved.

WhatsApp
A Levels Physics (9702)•9702/12/M/J/18
Question 17 from 9702/12/M/J/18

Explanation

Force equilibrium in horizontal and vertical directions

Steps:

  • Resolve forces vertically: tension's vertical component balances weight, so T cos θ = W.
  • Resolve forces horizontally: tension's horizontal component balances P, so T sin θ = P.
  • Divide horizontal by vertical equation: (T sin θ)/(T cos θ) = P/W, so P = W tan θ.
  • Substitute T from vertical: T = W / cos θ, confirming both relations in C.

Why C is correct:

  • Newton's first law requires net force zero; vertical equilibrium gives T cos θ = W directly from component resolution.

Why the others are wrong:

  • A: Swaps components; P equals T sin θ, not W cos θ, and T exceeds W.
  • B: Ignores angles; T ≠ P + W as forces are not collinear.
  • D: Incomplete and lacks P = W tan θ relation.

Final answer: C

Topic: Equilibrium of forces

Practice more A Levels Physics (9702) questions on mMCQ.me