Homework Statement
If tan(A+B) = 3 and tan(A-B) = 2, find tan2A and tan2B
Homework Equations
tan (A - B) = (tan A - tan B)/(1 + (tan A)(tan B) and similar sort of one for tan(A+B)
The Attempt at a Solution
i did some calculation and got tanA= (1-2tanB)/5tanB
after which there...
Homework Statement
A bomb is dropped from a plane flying horizontally with uniform speed. Show that the bomb will explode vertically below the plane.
Is the statement true if the plane flies with uniform speed but not horizontally?
Homework Equations
Equations of projectile perhaps...
Homework Statement
On boiling 1litre of N/5 HCl, the volume of the aqueous solution decreases to 250ml. If 3.65g of HCl is removed from solution, then the concentration of resulting solution becomes?
N/5
N/2.5
N/20
N/10
Homework Equations
HCl=36.5g/ mol
The Attempt at a Solution...
Homework Statement
A crew of an 8 oar boat has to be selected from 11 people, out of which 5 can oar only on one side, 4 can oar only on the other side and 2 can oar on either sides, find in how many ways can the selection be done?
The Attempt at a Solution
What I did here is assumed...
Homework Statement
how many 4 digit numbers are there which do not contain more than 2 different numbers?
Homework Equations
The Attempt at a Solution
all can contain the same digit
any 3 out of the 4 places can be occupied by the same digit
and
any 2 out of the 4 places can...
Homework Statement
There are 15 players, out of which 4 players own one 4 seater car each, and the car will be driven by the owner himself. In how many ways can they be seated in the cars?
Homework Equations
(3n)!/(n!)3
The Attempt at a Solution
i know that i have to substitute...
Homework Statement
find total sigma and pi bonds in c6h6
Homework Equations
Benzene structure
The Attempt at a Solution
if i consider benzene structure, then total will be 12σ and 3∏ but according to the random structure that i managed to draw, it showed, 11σ and 4∏, was i wrong...
Homework Statement
CH3CN [ in presence of aq. H2SO4 and 2H2O] → CH3COOH + NH3
The Attempt at a Solution
There is a triple bond present between Carbon and nitrogen, hence the first will be sp hybridized, while there is double bond between carbon and oxygen in the second, hence it should...
Homework Statement
In the hybradization of ethyne molecule, how many σ and ∏ bonds are being formed?
The Attempt at a Solution
Since, there is a triple bond between the carbon atoms, it should form 2 ∏ bonds and 1 σ bond.
Relatively there will be 2 other σ bonds between Carbon-Hydrogen...
yeah, got it! i was actually initially confused regarding that while typing, but now got it.
But while referring to the solution of this sum, they had considered the third excited state when n= 3, which i don't think is true, do you agree? it should be n=4
Homework Statement
For the third electron of Lithium atom moving in its permissible orbit, the values of angular momentum and the energy are?
Homework Equations
E= -2π2e4mZ2/n2h2
Third electron is in the second orbit
The Attempt at a Solution
The value for energy should be...
Homework Statement
On boiling 1litre N/5 HCl, the volume of the aqueous solution decreases to 250mL. If 3.65g of HCl is removed from the solution then the concentration of resulting solution becomes?
Homework Equations
No idea, from where should i start
Homework Statement
If there are 13 electrons in M shell and one electron in N shell, the the number of unpaired electrons in such atom will be
Homework Equations
M- shell N- shell
The Attempt at a Solution
The configuration should be
3s2 3p6 3d5 4s1
hence the answer should be 6
Homework Statement
The number of protons in nucleus of an element having maximum unpaired electrons in its 2P subshell are:
Homework Equations
Number of protons = no. of electrons in an neutral atom
The Attempt at a Solution
Maximum unpaired E.C. should 1s22s22p 3
Then, no. of...
Homework Statement
The concentration of Al3+ ion in aqueous solution of Al2(SO4)3 is 0.28M, Then the concentration of SO42- ion in this solution will be?
Homework Equations
Al2(SO4)3 → 2Al3+ + 3SO42-
The Attempt at a Solution
What should i compare to start of with?
Homework Statement
The number of moles of valence electrons in 1 mole nitride ions are?
Homework Equations
Nitride ion- N3-
The Attempt at a Solution
The number of electrons are 8.
Therefore number of moles should also be 8?
Homework Statement
The hydrogen electron de-excites from its 3rd excited state, which are the true and false statements for it.
1. It emits radiation giving lines in Lymann, Balmer, Paschen series
2. It emits radiation of only UV and Visible region and not Infrared region
3. It emits radiation...
Homework Statement
Lines li: ix+(i+1)y+(i+2)=0; i=1,2 intersect at___ point?
Homework Equations
The equation is required at first!
The Attempt at a Solution
I am confused!
How and where should I replace the values of i with 1 or 2?
This is the first step but i am unable to do...
This question is just to develop the thinking skill of the student!
It does not/ never is related to the original/factual happening around or perhaps inside the nucleus.
From where should i start.
I guess, the moment i get the completely filled configuration of noble gas, the number of...
Homework Statement
The angle made by angular momentum vector of an electron with Z- axis is given as ?
Homework Equations
angular momentum= √l(l+1) h/2∏
The Attempt at a Solution
So, I need to calculate the ratio of the energies of the two given?
if yes then, I did this at first but the answer given, i.e. 14.82 times larger was not obtained
Homework Statement
If each orbital can hold a maximum of 3 electrons, the number of elements in the 4th period of long form of periodic table will be?
Homework Equations
?
The Attempt at a Solution
I am not able to decide from where should I begin?
Homework Statement
How many times larger is the spacing between the energy levels with n=3 and n=8 spacing between the energy levels with n=8 and n=9 for hydrogen atom?
Homework Equations
En=Rh[1/ni2- 1/nf2]
The Attempt at a Solution
From the above stated equation, i managed to...
Homework Statement
The quantum numbers +1/2 and -1/2 for the electron spin represents?
Homework Equations
a) rotation of electron in clockwise and anticlockwise directions respectively
b) tow quantum mechanical spin states which have no classical analogue
c) Magnetic moment of electron...
Homework Statement
When the frequency of light incident on a metallic plate is doubled, the K.E. of the emitted photoelectrons will be?
Homework Equations
The answer should be either doubled or increased but more than double of the previous kinetic energy
The Attempt at a Solution
λ=...
Homework Statement
What possibility can be the ratio of the de Broglie wavelengths for electrons accelerated through 50 volts and 200 volts, initially having same wavelengths?
Homework Equations
I have literally no idea how to convert volts into energy, here i somewhat i think,
Energy=...
Actually, I would like to quote this to everyone who has helped me including you, Dharavbhai, that my first answer to the question, the moment I saw was 4m/s but it was not given in the options and plus, somehow i forgot to write that in the calculations done list as well!
the correct answer...
The answer what i got after considering 77eV as the kinetic energy, was not the original one, the answer should be 1.058m/s
I mentioned in my previous comments all the possible values that I managed to find, kindly check them and let me know if i have made a mistake, even the concept and its...
Homework Statement
Photoelectric experiment show that about 5eV of energy are required to remove an electron from platinum, if light of 150nm wavelength is used, what is the velocity of the emitted electron?
Homework Equations
de broglie's equation, E=hv
The Attempt at a Solution
Tried by...
I have only the intial velocity of the truck and that of the paedestrian, no final velocity!
How can I manage to calculate this without the final velocity?
Assume it to be 0?
What do you want me exactly to do?
As I had posted in the question itself, i had drewed the diagram, and perhaps imagine every incident that can take place in my mind,
but
any hints for getting the answer?
Homework Statement
A 2m wide truck is moving with a uniform speed v=8m/s along a straight horizontal road a pedestrian starts to cross the road with a uniform speed u when the truck is 4m away from him minium value of v?
Homework Equations
The equations of motion in a straight line, and...
I used the molecular mass of O as 16 to derieve the molecular masses of each element, where I have confusion is that after finding the molecular masses of the oxides, how can I find the valencies, means, how is the molecular mass related with valency?
Homework Statement
The oxides of a certain element contain 27.28%, 42.86% and 52.94% oxygen. What is the ratio of valencies of the element in the 3 oxides?
Homework Equations
The Attempt at a Solution
Following calculations were made:
Molecular mass of the first oxide is 58.6...
Homework Statement
A partially dried clay mineral contains 8% of water, the original sample contained 12% water and 45% silica. Then, the percentage of silica in the partially dried sample is nearly?
Homework Equations
Don't know if this is would help in the calculation,
in the original...