A 0.2 kg weight hanging over a smooth pulley is used to acceleration a 0.4 kg wooden trolley on a smooth table as shown.Suppose the weight has fallen a distance of 0.5m
(a)Now suppose the table is not smooth such that a friction of 0.3N is acting on the trolley ,find the work done against friction when the trolley moves a distance of 0.5m.
(b) By conservation of energy ,find the speed of the system when friction is present.
解下列物理問題
2007-01-03 6:16 am
回答 (2)
2007-01-03 7:10 am
✔ 最佳答案
Suppose the acceleration due to gravity g = 10ms-2(a)
Work done against friction
= F s cosθ
= (0.3)(0.5)
= 0.15 J
(b)
By Conservation of Energy
Lose in GPE of hanging weight - Work done against friction = Gain in KE of trolley
mgh - 0.15 = 1/2 m v2
(0.2)(10)(0.5) - 0.15 = (0.5)(0.4) v2
0.85 = 0.2v2
v = 2.06ms-1
Hope the above information helps =)
2008-12-25 7:29 am
I have a question
While the trolley are moving,the weight are also moving
Why doesn't the weight gain any kinetic energy?
While the trolley are moving,the weight are also moving
Why doesn't the weight gain any kinetic energy?
收錄日期: 2021-04-12 22:28:39
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