Physics · 2001 · November · Paper 3 · SL · Markscheme

MARKSCHEME November 2001 PHYSICS Standard Level Paper 3 21 pages N01/430/S(3)M INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL OPTION A — MECHANICS EXTENSION [1] A1. (a) for two point masses, the gravitational force is proportional to the product of the masses…; … and inversely proportional to the square of the separation of two masses; [1] Accept formula version for full marks provided the symbols are defined. [2 max] (b) SunEarth Moon arrow from centre of Moon towards centre of Earth; [1] arrow from centre of Moon towards centre of Sun; [1] Accept arrows if within half a radius of the centre. Correct idea but sloppy arrows should still gain credit. [2 max] (c) attempted use of 12 2 Gm mF r= for Earth / Moon AND Earth / Sun systems; [1] correct rearrangement; [1] ratio 22 23 11 2 30 8 5.98 10 1.5 10 1.99 10 3.84 10 SE SE rM Mr ××=×= × ××  to give ratio (no units); [1] 10.459 4.59 10 −== × [3 max] (d) Moon would (still) orbit the Sun; [1] time of orbit the same j 1 year or orbital distance roughly the same as before; [1] any relevant extra detail or explanation or discussion of ideas; [1] e.g. gravitational attraction to the Sun is still present etc. Actual answer depends on the velocity of the Moon when the Earth was ‘removed’, giving an elliptical orbit. Award fu ll marks to candidates who understand the principles but are unable to give a concise answer. N.B. reject the idea the Moon is kept in current orbit around the Sun as a result of its attraction to the Earth. [3 max] – 6 – N01/430/S(3)M