Question Discussion & Solution

Concept:

• Potential Energy: The energy of an object obtained by doing work against the conservative forces like spring force and gravitational force is called potential energy.
• The Gravitational potential energy of an object at a height h from the ground is given as

P = mgh

The spring potential energy of spring when it is stretched x distance from its natural length is given as

 \(P = \frac{1}{2}kx^2\)

• Kinetic Energy: The energy obtained by an object by virtue of its motion is called kinetic energy.

\(K = \frac{1}{2}mv^2\)

K is kinetic energy, v is the speed of the object, m is the mass of the object.

• Mechanical Energy: The sum of potential energy and kinetic energy is called mechanical energy.

Explanation:

So, from the above concept, it is clear that total mechanical energy is the sum of potential energy and kinetic energy. 

So, the answer is the Sum of Kinetic Energy and Potential Energy.

• Dioptre is the S.I. Unit of Power of a lens.
• A dioptre is equal to the reciprocal of the focal length measured in metres.
• Power of a lens is the ability of a lens to converge or diverge light rays depending on its focal length.

The correct answer is Gulab Kothari.

• Gulab Kothari was awarded Raja Ram Mohan Roy National Award 2019 for outstanding work in the field of journalism.

Key Points

• Gulab Kothari is an eminent Journalist and chairman of Rajasthan Patrika Private Limited.
• He was selected by the Press Council of India.

Additional Information

• Akkitam Achuthan Namboodari was a poet and essayist.
  • He was awarded the Jnanpith Award.

According to the given information,

Jaya ran faster than Sheetal

Jaya > Sheetal

Veena ran faster than Neha

Veena > Neha

Deepak ran faster than Neha but not as fast as Sheetal

Sheetal > Deepak > Neha

Sheetal ran slower than Veena but Veena is not the fastest.

Veena > Sheetal

Jaya > Veena > Sheetal > Deepak > Neha

Deepak came second last in the race.

The source of rain is clouds.

Similarly, the source of heat is fire.