# albertlee

Senior Members

1259

1. ## Why cannot the airplane accelerate for ever in the sky?

Thx for the reply froM skye, It is very useful. On the other hand, can any one explain to Me More clearly about the difference of Thrust and Drag about their forces and relationship? Say it More clearly, how are thrust and drag not equaled? very apreciate for the responds
2. ## About Metallic bonding...........

Siple as the title......... WHY ONLY PURE METALS USE THIS KIND OF BONDING? What is so special about the characteristics of pure Metals due to this kind of bonding? since why the non-Metals cannot use this type of bonding.....? thx for the responds
3. ## Why cannot the airplane accelerate for ever in the sky?

From skipower When u push the plane forwards, is'nt it also pushing air forwards? Then if so, does Newton's law still apply,here? if not, how and why? On the other hand, back to my first message, Can anybody give some mathematical calculations towards this topic? because all i got is just concept....but to me, i think we always measure in Physics........ Will Apreciate for the responds of all my questions Thx
4. ## About ions...(Quite challenged to answer, I think)

Is anion positive or negative?
5. ## About ions...(Quite challenged to answer, I think)

Another question about bonding...... Why only ionic compound dissolves in water, but not covalent compound? And likewise, why only covalent compound dissolves in petrol? I am not familar with solubility, please also tell me a concept about that..... Plz also answer my question of previous message MAny thanks.... Albert
6. ## Why cannot the airplane accelerate for ever in the sky?

These 2 possibilities is what bi can come up: 1) According to Newton's first law, if the force of the airplance is equaled to the force of the air, it goes in a straight line.... which means the air force (I mean not the millitary stuff ) also increases as the the force of the airplance increases.... but how can the airplane accelerate in the bigginning...? 2) According to Newton's third law, when the force exirting on the air, the air exerts back, but therefore the plane cannot even move, since the plane also exerting backwards and the air exerting back....... Anyway, ithink the reason for this is all about pressure of both (air + plane) and its transformation of force resulting the rate of air resistance........ Any way, back to my topic, please explain why..And tell me some specific ways of calculation to it Thx Albert
7. ## About ions...(Quite challenged to answer, I think)

WOW, Thanking YT. and Skye for the responds, i found them quite useful (although i am still not fresh, but i can grab the start ) Any way, for the negative ion, SO4, can i write it as O4S ? since O4 is considered to be positve....... Plz reply Albert
8. ## About ions...(Quite challenged to answer, I think)

Well....wolfson...it is not the answer i am seeking for, and it seems off-topic, because NaCl "is" a compound, and where Na and Cl are both ions....... but question is about compound ions..... for eg, OH, which is a compound ion..because it is negative charge....... Anyway, to answer my question......any needs to know what a compound ion is.... Any help? Albert
9. ## About ions...(Quite challenged to answer, I think)

Hello, My question is quite simple: HOW DO COMPOUND IONS FORM? i really want to know about the certainty of the formation about compound ions.... thx for the reply
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