Heavier objects always fall faster than lighter objects in air.
Which of the following statements is/are correct explanation?
1.There are some external forces acting on the objects,for example,the air friction.
2.A heavier objects has a larger uniform velocity when it falls freely.
3.A heavier objects has a larger acceleration due to gravity
A. 1 only
B. 2 only
C. 2 and 3 only
D. 1,2 and 3
answer is D
Can you explain why?
phy mechanics mc
2008-06-16 4:56 am
回答 (5)
2008-06-16 8:03 am
✔ 最佳答案
答案肯定不是D!!第3句很明顯是錯的.
任何物件的acceleration due to gravity 一定等於10 m s-2.
若有air friction存在, 也只是acceleration細了, 因不再等於acceleration due to gravity, 而是acceleration due to the resultant force.
答案應該是A
2009-04-18 8:19 am
一係岩既係呢三個當中。
二係錯既...FREE FALL 應該係無UNIFORM VELOCITY
三係錯既...GRAVITY , A=G=10MS^-2
BY F=MG
HEAVIER ONE ONLY HAS LARGER FORCE
一好似比較合理..ANS應該係A?
二係錯既...FREE FALL 應該係無UNIFORM VELOCITY
三係錯既...GRAVITY , A=G=10MS^-2
BY F=MG
HEAVIER ONE ONLY HAS LARGER FORCE
一好似比較合理..ANS應該係A?
2008-06-19 1:58 am
Yeah, Answer is A, not D.
1 is right
2 is not corect: not uniform velocity
3 is not correct: acceleration due to gravity is always 10ms-2
1 is right
2 is not corect: not uniform velocity
3 is not correct: acceleration due to gravity is always 10ms-2
2008-06-16 10:00 pm
A 唷。因v=開方2gh
2008-06-16 6:39 pm
但第二句沒有錯..
我覺得(1)(2)都對
2008-06-16 17:22:57 補充：
我指第二句啱ge意思係因為...Heavier objects 有大d ge 終端速度
終端速度=uniform velocity
我覺得(1)(2)都對
2008-06-16 17:22:57 補充：
我指第二句啱ge意思係因為...Heavier objects 有大d ge 終端速度
終端速度=uniform velocity
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