Recent content by chewchun

So option D is saying,When it is traveling upwards,net force/acceleration is acting downwards but it's magnitude is larger than 9.81 due to presence of air resistance?

Yes,but won"t it be that total downward force is larger than 9.81ms-2? But Option D seems to imply that it is accelerating upward.

Downward: Resistive force due to air resistance Gravitational force due to gravity Upward: Zero?

Homework Statement A ball is thrown vertically upwards and air resistance is NOT negligible.Which of the folloiwng statement is incorrect. A:At maximum height,acceleration is zero. B: Time taken for ball to travel upwards is shorter than time taken to travel down C: Distance traveled for...

Homework Statement 1:Over half a million tonnes of bromine are manufactured annually and are mainly used for making other compounds. One important use is for agricultural chemicals. What is another important use for bromine? a)antiseptic agents b)bleaches for textiles and the paper...

So the high resistance of voltmeter must play a role.what if there is no voltmeter,for instance just a strip wire...is experiment the same? Btw wouldn't the high resistance prevent current from flowing or something like that??

The answer was given to be D only. The carbon is directly bonded to oxygen,and the oxygen directly bonded to NO2.So it seems to be O- and NO2+?And i presume the O- to be created from a alcohol group and the H+ is removed... Answer is not C as the compound is trigonal planar and can be attacked...

In set-up with two half-cells and a voltmeter, the potential difference is measured using the voltmeter. But voltmeter has high resistance,which i know is still able to measure potential difference,but wouldn't it prevent electrons from flowing What i meant was,the use of voltmeter creates a...

Homework Statement But-2-ene reacts with bromine in the presence of concentrated aqueous sodium nitrate to give the following compound CH3-C(H)(ONO2)-C(H)(Br)-CH3 Which of the following statement is correct. a.the electrophile is NO2+ b.Only 2,3-dibromobutane is formed. c.Resultant...

thanks a lot,totally got it!

I don't think so...sodium should be oxidised,but naoh contains sodium ion...

Oh,so its that 1 photon may not eject a photoelectron at all??! I guess I am asking too much,even my teacher does not want to discuss this with me...!(Or he doesn't know!)

Quantum efficiency,i presume to be the fact that 1 photon can eject 2 photoelectrons? And WHAT IF my power vary with frequency? Or is power proportional to intensity? What are the other issues?

Is there any reason for the high activation energy of methane combustion? To me,such a simple molecule seems to be pretty complex upon what you have said...

Methane burns at 1200k without any spark or ignition. But why is this so?Why so high temperature? Isn't it that when there is the right proportion of methane and oxygen, combustion will occur with a small energy needed? Or is it because of high activation energy?