(1) ํž˜์˜ ํ‰ํ˜• ์ด์šฉ

m+M=3/4Mg + 9/20Mg => m=1/5 M

(2) A๋ฅผ ์ถ•์œผ๋กœ ๋Œ๋ฆผํž˜ ๋ณ€ํ™”๋Ÿ‰ ์ ์šฉ

1/2 * 5F/M * t0^2 * Mg/5 = 20 * L (1/2Mg-9/20Mg) => F=2ML/t0^2


200620๊ณผ ๋™์ผํ•œ ์•„์ด๋””์–ด์ž„ ใ…‹ใ…‹

ํ•œ ์ƒํ™ฉ์—์„œ ๋‹ค๋ฅธ ์ƒํ™ฉ์œผ๋กœ ๋ณ€ํ•  ๋•Œ๋Š” ๋Œ๋ฆผํž˜ ๋ณ€ํ™”๋Ÿ‰์„ ์ด์šฉํ•˜๋Š” ์Šต๊ด€์„ ๋“ค์—ฌ๋ณด์ž.