Physicsfan

Can you not try another method of preparing [ce]NO2[/ce]? you can just add nitric acid to the container and let it stand for sometime. It decomposes into nitrogen dioxide and Oxygen, and the nitrogen dioxide dissolves again in nitric acid. the process the repeats

If you just dip some papers in water i think you would get a solution. then you could crystallize it by evaporating the water. why dont you buy some?

Why not water? moist filter paper perhaps? Is it really necessary to use dry filter?

with respect to the bullet.and the bullet is moving in a direction opposite to that of the train, that is, opposite to the direction of the person moving with the train. if by forward you mean in the direction of the train, then i thought the velocity of the bullet as seen by the passenger was 400m/s, because the passenger is already moving at a speed of 100m/s. Merged post follows: Consecutive posts mergedwhen two bodies are moving with different velocities relative to the same thing in the same direction,the their velocities with repect to each other would be obtained by subtracting the two velocities right?

I was talking about firing the bullet in the direction opposite to that of the train.is that what you are talking about too?

Ok.But as Leader Bee said, the train is enclosed.So the velocity of the bullet as seen by the person inside the train is th muzzle velocity,because the bullet accelarates relative to the gun and the gun is stationary with respect to the person.is this right? But as the bullet moves in one direction, then the person is moving in the opposite direction.So to the velocity of the bullet as seen by the person is the velocity of the bullet+the velocity of the train, right?

I think the velocity with respect to the surrounding would be the same,but with respect to the person in the train it would be faster. if fired in a direction opposite to the train Merged post follows: Consecutive posts merged wont the velocity of the gun be the same as that of the train?

what would the speed of the bullet with respect to the surrounding outside the train be like if it is fired in a direction opposite to the direction of the moving train? but if the bullet was fired at a target in the train, then the bullet would hit the target with the same velocity as if it were fired from outside.

Oh! i didn't consider that. So when two bodies fall freely, they do not exert a force on each other. is that because the accelaration of the first body with respect to the second is zero?

According to me it should fly up to the ceiling Merged post follows: Consecutive posts mergedbecause the the elevator would already have gained more velocity by then

how about this situation: the football player drops the ball a few seconds after the chain breaks

Imagine a foot ball player enters an elevator holding the ball.The elevator chain breaks and at that same instant he drops the ball to the elevator floor.will the ball ever fall to the floor?

Ammonia dissolves in water to give ammonium hydroxide. Thats the reason why it turns moist red litmus blue. By Lowry Bronsted theory bases are proton acceptors. ammonia accepts a proton from water(hydrogen ion). Ammonia also accepts hydogen ions from acids and forms the respective ammonium salts. Ammonia can also behave as a weak acid: [ce]2Li + 2NH3 -> 2LiNH2 + H2[/ce]

i can take the net effort to be 6x. So now i get a single variable for effort. but then again ill have to consider another variable for displacement.

If force required to overcome friction was x N, the total effort would be (E+x)N. so M.A=L/(E+x)=(5/6)*V.R. =(5/6)*(ideal M.A). =(5/6)(L/E). 6E=5E+5x E=5x now is it possible to solve?

so it is an approximation then! nice web page thank u!

no. i was talking about 1/infinity.thats what i was actually asking about.(refer to my first post) this question hit me because if tan 90 is infinite(theoretically) then cot 90 is 1/infinite right? so how should i explain this?

the "number" would be the quotient. So, my statement and yours would mean the same. Because both equal infinity. this kind of concept is also seen in reflection between two parallel mirrors. (360/0)-1=infinity.(0 is the angle between the two mirrors.) thats the reason we get countless images when we stand between two parallel mirrors.

Isn't division by zero similar to asking "how many points there are in a line"? that would be infinite wouldn't it?

but devision by zero is taken as infinity in trignometry. tan 90 for example.

anything by zero is infinity.but is anything by infinity zero?

the AO/K=AI part is the problem. that part is where i get stuck.

In reactions such as the reaction of iron with dilute acids, Fe 2+ salts are formed. but if an aqueous solution of an Fe 3+ salt undergoes a double decomposition reaction with an aqueous solution of another salt,(or with strong alkalis such as NaOH) the Fe 3+ salts are formed(with a different anion).

no. this question appeared in our 9th grade final exams so the question cannot be wrong. I do not know how many blocks there are because the question does not mention that. the net work done by the effort would be 12000J. so the efficiency of the system would be 10000J/12000J=M.A/V.R. Using this relation, is it possible to find the displacement of effort?

Ok. Now this is the image Ok. this is the image. This is how i understand it the refractive index of water will be equal to sin r/sin i = (AO/sin i)/(AO/sin r)=K. Now sin i=AB/OB, and sin r=AB/IB. So numerator =AO/(AB/OB)=(AO*OB)/AB. denominator=AO/(AB/IB)=(AO*IB)/AB. So the refractive index is AO*OB/AO*IB=K. =>OB/IB=K Also, AO*OB/(AO/K)*KIB=K So AO/(AO/K)=K (Is this correct?) If correct, then AO/K=AI. so refractive index=AO/AI. If all this is correct, then can suggest me a simpler way of deriving this expression? Thank u refraction.psd