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Does the left red wheel turn in the same direction as the leftmost orange wheel?If so P and S go up? If not, Q and S go up?

My reasoning:

If so

  1. Leftmost orange cc
  2. Left red cc (by assumption)
  3. Leftleast orange clock --> P goes up
  4. Gray cc
  5. Right least orange clock
  6. Right most orange clock (similar to assumption)
  7. Right red cc --> s goes up

If not

  1. Leftmost orange cc
  2. Left red clock
  3. Leftleast orange cc --> Q goes up
  4. Gray clock
  5. Right least orange cc
  6. Right most orange clock (similar to assumption)
  7. Right red cc --> s goes up
  • $\begingroup$ This looks more like a GCSE (or earlier? Key Stage 3?) physics exam question to me, although googling "ICAS" gives me "The Institute of Chartered Accountants Scotland"... Not personally convinced this is a great fit for engineering.SE. $\endgroup$ – AndyT Jan 30 '17 at 17:03
  • $\begingroup$ @AndyT migrate to physics SE please? $\endgroup$ – BCLC Jan 30 '17 at 17:06
  • $\begingroup$ @AndyT If it's about manipal.edu/mu/lp/ICAS-International-engineering.html, then it was engineering - but the best place for it on SE is a different question. $\endgroup$ – alephzero Jan 30 '17 at 19:33

When two wheels/pulleys/cogs are connected by a belt, when one of the wheels turns the other one turns in the same direction as the first wheel that turns.

When two cogs/gears are positioned so they are touching, when one cog is turned in one direction the other cog turns in the opposite direction.

So for your example:

  1. The upper left yellow cog turns counter clockwise (ccw)
  2. Because its connect to the red cog via a belt, the red cog also rotates ccw and the middle yellow cog turns clockwise (cw) causing weight P to rise.
  3. Because the middle yellow cog rotates cw the black cog rotates the opposite direction, ccw. This causes the upper right yellow cog to turn cw.
  4. The upper right yellow cog is connected to the lower right yellow cog via a belt, so the lower right yellow cog also turns cw.
  5. The lower right yellow cog touches the lower right red cog which then turns the opposite direction, ccw.
  6. This results in weight S being raised.

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