Homework Help > CBSE > Class 11
Ask questions which are clear, concise and easy to understand.
Elucidate the Paralympic games in detail.

Answers:
How can i download the solutions of the book 'elements of mathematics' of class 11?

Answers:
A body covers 20 m distance in first 2 secs and 40 m distance in next 3 secs.Find its initial velocity and acceleration

Answers:

Let initial velocity = u
Acceleration = a
Using equation
{tex}s = ut+{1\over 2}at^2{/tex}
For first 2 sec
{tex}20 = 2u+{1\over 2}4a{/tex}
{tex}20 = 2u+2a{/tex}
{tex}10=u+a \ ....... (1){/tex}
Now distance covered in 2 to 5 sec is given 40m
{tex}40 = 5u+{1\over 2}25a20{/tex}
=> 120 = 10u +25 a
=> 24 = 2u+5a ....(2)
Solving (1) and (2), we get
{tex}a= {4\over 3}\ m/s^2{/tex}
And u {tex}={26\over 3}\ m/s{/tex}
Thanks (2)
Name the famous emperors of early roman empire.discuss their contributions in making roman empire

Answers:

I am not sure but I think the king,'s name is Romulus .
Thanks (0)
many of them need commerce vidios becouse now a students take commers so you wants to make commerce main subject vidios from examfear are by your self and because of exam fear and by cbse guide i got 10 cgpa in my 10 class

Answers:

good
Thanks (0)
We have to prepare a solution of 0.2M NAOH from the available 1M solution that is given to us how much volume of 1M NAOH is required to be taken which contains 0.2 moles of sodium hydroxide

Answers:

1M solution of NaOH means that 1 litre of solution has 1 mole of NaOH.
We need 0.2 mole of NaOH.
Since 1 litre contains 1 mole NaOH , so 0.2 litre will contain 0.2 moles.
Thanks (0)
A body travels a distance of 2 meters in a second and 2.2 meters in next 4 seconds what will be the velocity of the body at the end of 7 seconds from the start

Answers:

s= ut + 1/2 a t^2 u is the initial velocity and a is the acceleration.
The first relation you for 2 m
2 = u 2 + 1/2 a 2 *2
1= u + a
For the second relation
we get
5 seconds after, i.e. 7 seconds after it covered the distance 2+2.2
You get
4.2 = u *7 + 1/2 a *7*7
8.4 = 14 u + 49 a
We got two relation
u+a= 1
14 u + 49 a = 8.4
Sol;ve for a and u. You get
u = 29/25 and a = 4/25
The velocity V at the end of the 7th sec will be
V= 29/25  4/25 *7 = 1/25 m/sThanks (0)
How do determine the domain and range of a function. Please also give some examples

Answers:
Method to write Cartesian product of two sets. And please give me a example of the question.

Answers:

In <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Set_theory&hl=enIN">set theory</a> (and, usually, in other parts of <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Mathematics&hl=enIN">mathematics</a>), a Cartesian product is a <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Mathematical_operation&hl=enIN">mathematical operation</a> that returns a <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Set_(mathematics)&hl=enIN">set</a> (or product set or simply product) from multiple sets. That is, for sets Aand B, the Cartesian product A × B is the set of all <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Ordered_pair&hl=enIN">ordered pairs</a> (a, b) where a ∈ A and b ∈ B. Products can be specified using <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Setbuilder_notation&hl=enIN">setbuilder notation</a>, e.g.
{\displaystyle A\times B=\{\,(a,b)\mid a\in A\ {\mbox{ and }}\ b\in B\,\}.}
<a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Cartesian_product%23cite_note1&hl=enIN">[1]</a>
A table can be created by taking the Cartesian product of a set of rows and a set of columns. If the Cartesian product rows × columns is taken, the cells of the table contain ordered pairs of the form (row value, column value).
More generally, a Cartesian product of nsets, also known as an nfold Cartesian product, can be represented by an array of n dimensions, where each element is an n<a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Tuple&hl=enIN">tuple</a>. An ordered pair is a <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Tuple%23Names_for_tuples_of_specific_lengths&hl=enIN">2tuple or couple</a>.
The Cartesian product is named after <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Ren%25C3%25A9_Descartes&hl=enIN">René Descartes</a>,<a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Cartesian_product%23cite_note2&hl=enIN">[2]</a> whose formulation of <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Analytic_geometry&hl=enIN">analytic geometry</a> gave rise to the concept, which is further generalized in terms of <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Direct_product&hl=enIN">direct product</a>.
Examples
A deck of cards
<a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/File:Piatnikcards.jpg&hl=enIN"></a>
Standard 52card deck
An illustrative example is the <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Standard_52card_deck&hl=enIN">standard 52card deck</a>. The <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Playing_cards%23AngloAmerican&hl=enIN">standard playing card</a>ranks {A, K, Q, J, 10, 9, 8, 7, 6, 5, 4, 3, 2} form a 13element set. The card suits {♠, ♥, ♦, ♣} form a fourelement set. The Cartesian product of these sets returns a 52element set consisting of 52 <a href="https://googleweblight.com/i?u=https://en.m.wikipedia.org/wiki/Ordered_pairs&hl=enIN">ordered pairs</a>, which correspond to all 52 possible playing cards.
Ranks × Suits returns a set of the form {(A, ♠), (A, ♥), (A, ♦), (A, ♣), (K, ♠), ..., (3, ♣), (2, ♠), (2, ♥), (2, ♦), (2, ♣)}.
Suits × Ranks returns a set of the form {(♠, A), (♠, K), (♠, Q), (♠, J), (♠, 10), ..., (♣, 6), (♣, 5), (♣, 4), (♣, 3), (♣, 2)}.
Both sets are distinct, even disjoint.
Thanks (0)
Paid rent in advance how it is show in accounting equation

Answers:

It is an expense but the benefit of the same will in next period so it is shown as an assets.
So add to asset "Miscelleneous Expenditure" part.
Thanks (1)
Is independent thinking a step towards adulthood if so, elucidate, in context of the poem "childhood" by Markus natten

Answers:
Khuswant Singh's grandmother was neligious and kind lady. Cite example from the lesson to support your viewpoint.

Answers:

Khuswant Singh's grandmother was really a religious & kind personality. She regularly visited the temple for morning prayers & always carried some stale chappaties for the street dogs. She regularly used to fed to the birds. Her mouth was always engaged in inaudible prayers & her hands kept on telling the beads of her rosary.
Thanks (2)
हिंदी की पुस्तक अंतरा के प्रथम पाठ ईदगाह के प्रश्न उत्तर

Answers:
Electronic configurstion of Re Rhenium (z=75).

Answers:

{tex}1s^22s^22p^63s^23p^63d^{10}4s^24p^64d^{10}\\5s^25p^64f^{14}5d^56s^2{/tex}
Thanks (0)
A car is travelling at a speed of 30 km/h is brought to rest in a distance of 8 m by applying brakes. If the same car is moving at a speed of 60 km/h then it can be brought to rest with the same brakes in what distance?

Answers:

33.3 m
Thanks (0) 
First case:
Initial velocity u = 30 km/h {tex}= {25\over 3}\ m/s{/tex}
As it stops so Final velocity v = 0
time taken t = 8 m
Acceleration of car = a
We know,
{tex}a = {vu\over t}{/tex}
={tex}{25\over 24}\ m/s^2{/tex}
Second case :
As same breaks applied so acceleration is same.
initial velocity u = 60 km/h {tex}={50\over 3}\ m/s{/tex}
As it comes to rest so final velocity v = 0 m/s
Distances covered before rest = s
We know,
{tex}v^2u^2= 2as{/tex}
=> {tex}(0)^2({50\over 3})^2= 2\times {25\over 24}\times s{/tex}
{tex}=> s ={2500\over 9}\times {24\over 25}\times {1\over 2}{/tex}
= 33.3 m
Thanks (0)
The photograph of a house occupies an area of 1.75 cm² on a 35 mm slide. The slide is projected on to a screen and the area of the house on the screen is 1.55 m² . What is the linear magnification of the projector screen arrangement?

Answers:

Area of photo=1.75 cm^{2}=1.75×10^{4}m^{2}
Area of image of photo=1.55m^{2}
Magnification (areal)=1.55/1.75×10^{4}=0.885×10^{4}
Magnification(linear)=√areal magnification
=√0.885×10^{4}
=0.94×10^{2}
Thanks (1)
उसके अंदर प्रकाश है बाहर आशा विपत्ति अपना सारा दलबल लेकर आए हामिद की आनंद भरी चितवन उसका विध्वंस कर देगी इस कथन के आधार पर स्पष्ट कीजिए कि आशा का प्रकाश मनुष्य को विपरीत परिस्थितियों में भी निरंतर आगे बढ़ने की प्रेरणा देता है

Answers:

जीवन में आशा का प्रकाश सदैव फैला रहता है। आशा रूपी प्रकाश हमें निराशा के क्षणों से बाहर ले जाता है और हमें जीवन में आगे बढ़ाता है। कई बार ऐसी विषम परिस्थितियाँ सामने आ खड़ी होती हैं कि मनुष्य की सोचनेसमझने की शक्ति समाप्त हो जाती है। ऐसे में आशा की किरण उसे विषम परिस्थतियों से बाहर निकाल लेती है।
जो व्यक्ति निराशावादी है, वह आगे नहीं बढ़ सकता है। वह हार मान जाता है और लड़ना छोड़ देता है। मगर जिस मनुष्य ने आशा का दामन थाम लिया है, वह कभी हार नहीं मानता और निरंतर आगे बढ़ता चला जाता है। वह जानता है कि उसकी मेहनत रंग अवश्य दिखाएगी। बस यही आशावादी सोच उसे बाहर निकाल लेती है और वह जीवन में निरंतर प्रेरणा स्रोत पाता है। हामिद के मातापिता उसके संग नहीं हैं।
उसके पास यह आशा है कि एक दिन उसके मातापिता अवश्य लौटकर आएँगे। यही किरण उसे सदैव प्रसन्न रखे हुए है। वह अभावों की जिंदगी जी रहा है मगर उससे उसे कोई फर्क नहीं पड़ता। वह जानता है कि एक दिन उसके दिन अवश्य बदलेंगे। उसका यही विश्वास विपत्ति को उसके आगे घुटने टेकने पर विवश कर देता है।
Thanks (0)
A body is thrown from a tower it covers 40m in last 2 second find height of tower

Answers:

Let h be the height of the tower and t the time taken
u=0 and g= 10m/s^{2}
Using S= ut +1/2 gt^{2}
h= 0+5t^{2} (1)
distance travelled in last 2 seconds is 40 m
again using S= ut +1/2 gt^{2}
h40= 0+5(t2)^{2} (2)
subracting 2 from 1
hh+40= 5(t^{2}  (t2)^{2}
8= (t^{2}  (t2)^{2}
8= 4t4
t=3
substituting t in equation 1
h= 5x 3 x 3= 45 m
Height of tower = 45 m
Thanks (0)
What is centrifeugal force.?

Answers:

Centrifugal force is defined as, “The apparent force, equal and opposite to the centripetal force, drawing a rotating body away from the center of rotation, caused by the inertia of the body
Thanks (0) 
A force, arising from the body's inertia, which appears to act on a body moving in a circular path and is directed away from the centre around which the body is moving.
Thanks (0)
How do changing anatomy and physical features indicate evolutionary stages in the evolution of humans?

Whatvhappen to answer ?any thank u for lying!
 Add Comment

Answers:
How early man obtain food?

Answers:

Earlu humans generally hunted animals. Later on they started making tools by themselves and also were able to distinguish between poisonous and nonpoisonous animals. Also satrted searching for food products in the jungles and when they got it they preferred to eat it for a long time.
Thanks (0)
In what basis chemical equation divided into two or more chemical equations in partial equation method of balanced equation?

Answers:

Partial equation method:
Partial equation method is used for balancing complex chemical equations. There are chemical equation which involves many steps and reacting elements occur in more than one products in the product side. In such cases, balancing by Hit and Trial method is difficult. That is why partial equation method is used to balance such chemical equations.
In Partial equation method, equation is first divided into partial equation, which are simply probable steps that might occur in the chemical reaction. These probable steps are then balanced by hit and trail method and finally added. Following steps are applied in balancing chemical equation by partial equation method.
 At first, different probable steps are written for the given chemical equation. These probable steps are simply the partial chemical equation which we can write for easily balancing the reactants and product. Note that the probable steps may or may not occur in real.
 After breaking down the probable steps for the chemical equation, the partial equations are individually balanced by using Hit and Trial Method.
 Such balanced partial equations are multiplied by suitable integer. This is done if required, so that the elements which are not formed in the product side of the overall chemical equation is canceled out.
 Finally, the balanced partial equations are added to get the final overall balanced equation.
Lets’ illustrate some examples:
PbS + O3 →PbSO4 + O2
In the given reaction, the atom of Pb and S is balanced in both reactant and product side. But there is 3 atom of oxygen in reactant side and 6 oxygen atom in product side. So let’s balance this chemical equation by partial equation method.
 First let’s think the possible step for occurring of the given chemical reaction. There is lead sulphide reacting with ozone, it means ozone must be acting as oxidizing agent which liberates nascent oxygen. So the first step can be generation of nascent oxygen by decomposition of ozone molecule.
Step1
O3 →O2 + [O]
This liberated nascent oxygen can react with PbS to give lead sulphate and oxygen as;
Step2
PbS + [O] → PbSO4
This partial step is not balanced reaction. There is equal number of Pb and S atom, but no. of oxygen is one in reactant side but four in product side. So we can multiply nascent oxygen in reactant side by four.
PbS + 4[O] → PbSO4
If we make four nascent oxygen in second probale step, then we must also need to make it equal number of nascent oxygen liberated in step one. So we need to multiply step one with integer four
{ O3 →O2 + [O] } × 4
Now lets add both partial equation:
{ O3 →O2 + [O] } × 4
PbS + 4[O] → PbSO4
PbS + 4O3 PbSO4 + 4O2
This is the balanced chemical equation.
Thanks (1)
Explain aram's experience riding the horse on his first day?

Answers:
How can we know that we have to use integration or differentation?

Thankyou Sachin.
 Add Comment

Answers:
A man can swim with a speed of 4km per hour in still water. How long does he take to cross a river of 1 km width given speed of river is 3 km per hour??

Answers:

Speed of the man, v_{m} = 4 km/h
Width of the river = 1 km
Time taken to cross the river = {tex}Width\ of \ the \ river \over Speed \ of \ the \ river {/tex}{tex}= { 1\over 4} h ={ 1 × 60 \over 4 }= 15\ min{/tex}
Thanks (0)