[ملاك1]

اولا السلام عليكم ورحمة الله وبركاته
المسألة الاولى :
A balloon is filled with helium . it's volume is 1.00 m3 ......... what down word force must be applied to stop the balloon rising up into the sky ...........
( density of air = 1.29 kg/ m3 )
( density of helium = 0.18 kg/m3 ) ????

المسألة التانية :
two masses are connected by alight that passes over a frictionless pulley , as in figure , if the incline is frictionless and if m1 = 2.00 kg , m2 = 6.00 kg , and (tita) =55 degree ,,,,,,, find :
1) the acceleration of masses
2) the tension in the string
3) the speed of each mass 2 s after being released from rest ?
توجد رسمة لكن لاأعرف كيف ارسمها ... اتمنى ان تكون المسألة واضحة من غير الرسم

المسألة التالثة :
where must a weight be hung on a pole , of negligible weight ,, so that the boy at on end supports 1/3 as much as the man at the man at other end ??
يضا هنا توجد رسمة ... لكن اتمنى ان تستطيعو حلها من دونها.....

اتمنى منكم المساعدة بما أستطعتم ولكم مني خالص الشكر والتقدير
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