Explore topic-wise InterviewSolutions in .

D) 300%

Explanations:

p = 100% x p + p

 =2p

K'=(p')²/2m

 =4p²/2m

4K=3K +K

=300% K + K

= 300% K+K

KE becomes four times. It means that the kinetic energy increase by 300%.

We know that F α l

i.e. F = k l

∴ For a given force, k α \(\frac {1}{l}\) since extension a length. If length is halved then the spring constant doubles.

We know that KE = \(\frac{p^2}{2m,}\)

given p is same 

∴ k E α \(\frac{1}{2m}\)

∴ Lighter body will have greater kinetic energy.

(c) -9 ms^-1 and 5 ms^-1

Here, p_i = p_z , m₁v₁ = m₂v₂

∴ \(\frac{v_2}{v_1}=\frac{m_1}{m_2}..........(i)\)

As \(E_2=\frac{1}{2}m_2v^2_2\)

and \(E_1=\frac{1}{2}m_1v^2_1\)

∴ \(\frac{E_2}{E_1}=\frac{\frac{1}{2}m_2v^2_2}{\frac{1}{2}m_1v^2_1}\)

\(=\frac{m_2}{m_1}(\frac{v_2}{v_1})^2\)

using (i) \(\frac{E_2}{E_1}=\frac{m_2}{m_1}\times(\frac{m_1}{m_2})^2\)

If m₁ < m₂, E₂ < E₁

or E₁ > E₂

i. e., lighter body has more K.E.

D) 300%

Explanations:

p'=100% x p+p

=2p

K'=(p')² /2m

=4p² /2m

4K= 3K + K

=300% K + K

KE becomes four times. It means that the kinetic energy increases by 300%.

Bombay became an attractive destination for people seeking jobs after the British administration replaced Surat with Bombay as its principal western port. The consequent increase in trade and industries led to a great influx of people. Thus, migrants were (and still are) an important facet of Bombay. Most of the people in the film industry were migrants themselves, and wanted to portray the plight of this class of people through films. Thus, a number of Bombay films were about the lives of migrants.

In mid-seventeenth century, Bombay became East India Company’s principal western port, replacing Surat. Later, by the end of the nineteenth century, it had become an important administrative as well as industrial centre. All through these years, the prospects for trade and commerce, and employment kept increasing, thereby making Bombay an attractive destination for migrants.

Government laws play an important role in controlling the rates of pollution in a city. However, simply passing laws is not enough. They need to be properly enforced as well. It is also a fact that people tend to find ways of getting around laws. So, apart from legislations, government also needs to carry out intensive public awareness programmes aimed at educating the public about the need and ways of controlling pollution; and about how they too have a stake in environmental governance. Example to show the success of legislation to change the quality of

Public life - The Bengal Smoke Nuisance Commission, established as per the Bengal Smoke Nuisance Act of 1905, was successful in controlling industrial smoke in colonial Calcutta.

Private life - The British government passed the Clean Air Act in 1956. This law was aimed at controlling domestic sources of smoke pollution, and to do so, it introduced the concept of smokeless zones. In these areas, smokeless fuels had to be burnt. As a result, air pollution in British cities was substantially reduced. Example to show the failure of legislation to change the quality of Public life - By the 1840s, British cities such as Derby, Leeds and Manchester had smoke control laws in place. However, these laws did not succeed much in controlling smoke emission. Since smoke is not easy to monitor or measure, it was easy for factory and steam engine owners to get away with small adjustments to their machinery, and this did nothing to stop smoke.

Private life - During the colonial period, a huge population depended on dung and wood as fuel in their daily life. This was an important source of air pollution in Calcutta. Though successful in controlling industrial smoke, the Bengal Smoke Nuisance Commission found it difficult to control this domestic smoke.

[Note: The following can also be a possible answer to the second part of this question.]
Example to show the success of legislation to change the quality of

Public life - The British state used public funds to provide for entertainment forms such as museums, art galleries and libraries for the working classes.

Private life - British administrative officials built houses in new suburbs for fulfilling the housing needs of the working classes. Example to show the failure of legislation to change the quality of

Public life - The Underground railway enhanced transport, but caused the demolition of many houses, rendering their inhabitants homeless.

Private life - The availability of one-room tenements and no housing facilities for a major part of the industrial revolution time period caused the family to get divided into smaller units. There were even cases where rural people had to leave their families behind and live alone in the urban areas where they worked.

The people in the chawls of Bombay entertained themselves in the following ways. 

• Streets were used for different leisure activities. Magicians, monkey players or acrobats performed their acts here.
• People used to exchange news about jobs, strikes, riots or demonstrations. 
• Liquor shops and akharas too came up where people spent their time.

(i) Bombay as capital city : Bombay became the capital of the Bombay Presidency in 1519. after the Maratha defeat in the Anglo – Maratha war. The city quickly expanded. With the growth of trade in cotton and opium, large communities of traders and bankers as well as artisans and shopkeepers came to settle in Bombay. 

(ii) Industrialisation: The establishment of textile mills led to a fresh surge in migration. The first cotton textile mill in Bombay was established in 1854. By 1921, there were So cotton mills with about 1,46,000 workers. Only about one-fourth of Bombay’s inhabitants between 1881 and 1931 were born in Bombay ,the rest came from outside. Large numbers flowed in from the nearby district of Ratnagiri to work in the Bombay mills. 

(iii) Introduction of railways: The first railway was introduced from Bombay to Thane in 1853 It was at the junction head of two major railways. The development of railway encouraged an even higher scale of migration into the city. 

(iv) Famines: Famines in the dry regions of Kutch drove large number of people into Bombay in 1888-89. The flood of migrants in some years created panic and alarm in official circles. 

(v) Bombay as a film city: By 1925. Bombay had become India’s film capital. Most of the people in the film industry were themselves migrants who came from cities like Lahore. Calcutta. Madras, etc

The following were the three features of chawls of Bombay. 

• Chawls were multi-storeyed structures that had been built from at least the 1860s in the native parts of the town. 
• Each chawl was divided into smaller one-room tenements, which had no private toilets.
• Chawls were also the place for the exchange of news about jobs, strikes, riots or demonstrations.

The following were the three characteristics of the ancient cities. 

• Towns and cities, that first appeared along river valleys, such as Ur, Nippur and Mohenjodaro in ancient times, were larger in scale than other human settlements of those times. 
• There were certain conditions needed for the development of ancient cities. It could develop only when an increase in food supplies made it possible to support a wide range of non-food producers.
• Cites were often the nucleus of political power, administrative network, trade and industry, religious institutions, and knowledge production. It supported variegated social groups such as artisans, merchants and priests.

Yes, mass is converted into mass energy in an exothermic chemical reaction also.

But the mass change in a chemical reaction is about a million times less than in a nuclear reaction.