Tag: energy for everything

Questions Related to energy for everything

A ball is dropped from $30\ m$ on hitting the ground if it loses $40$% of its energy, it rebounds to a height equal to

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. $12\ m$

  2. $15\ m$

  3. $18\ m$

  4. $16\ m$

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Correct Option: A

A small sphere is moving at a constant speed in a vertical circle. Below is a list of quantities that could be used to describe some aspect of the motion of the sphere.
$I$   -kinetic energy
$II$  -gravitational potential energy
$III$  - momentum
Which of these quantities will change as this sphere moves around the circle?

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. $I$ and $II$ only

  2. $I$ and $III$ only

  3. $III$ only

  4. $II$ and $III$ only

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Correct Option: D
Explanation:

Speed is given as constant. Though the velocity is changing only in direction, its magnitude remains the same. Thus the kinetic energy remains constant as it is a scalar quantity but momentum would change as it is a vector quantity.
Also as the elevation of the ball keeps on changing during the motion, the potential energy changes

Energy required to break a bond of DNA is approximately

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. ~ 1 eV

  2. ~ 0.1 eV

  3. ~ 0.01 eV

  4. ~ 2.1 eV

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Correct Option: A
Explanation:

The bond energy of a DNA molecule is 1 eV, so this will be the energy required to break the bond

A system absorbs 600 J of energy and does work equivalent to 400 J of energy. The internal energy change is

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. 1000 J

  2. 200 J

  3. 600 J

  4. 300 J

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Correct Option: B
Explanation:

$\begin{array}{l} We\, \, know\, \, that, \ \Delta E=Q+W \ =600+\left( { -400 } \right)  \ =200J \end{array}$

Hence,
Option $B$ is correct.

On a microscopic scale, all forms of energy may be studied as

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. potential

  2. kinetic

  3. potential or kinetic

  4. nuclear

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Correct Option: C
Explanation:

On microscopic level all energies are either Kinetic or potential as they are either created due to motion or particle interaction.

Raindrops fall on earth with certain kinetic energy on the earth. From where do they get this energy ?

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. Chemical energy

  2. Gravitational Potential energy

  3. Energy between molecules of water

  4. Heat energy

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Correct Option: B

Water stored in a dam primarily possesses

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. Heat energy

  2. Electrical energy

  3. Kinetic energy

  4. Potential energy

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Correct Option: D
Explanation:

Answer is D.

Potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height.
There is potential energy stored in a water reservoir behind a dam. It is converted to kinetic energy when the water starts flowing down the penstock, from the dam. This kinetic energy is used to turn a turbine.
Hence, the water stored in a dam possesses potential energy.

The form of energy that wood can be categorized into is:

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. chemical energy

  2. electrical energy

  3. potential energy

  4. muscular energy

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Correct Option: A
Explanation:

You'd burn it, just like you might burn coal or oil or natural gas. The stored energy in the wood is chemical energy, meaning that it can be released by a chemical reaction (burning). It's closely related to those fossil fuel energies, because the chemical energy was formed by photosynthesis, using energy from sunlight as the input.

An atom bomb converts __________ into heat and sound energy.

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. electrical energy

  2. heat energy

  3. mechanical energy

  4. atomic energy

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Correct Option: D
Explanation:

An atomic bomb contains atomic energy which is converted to heat and sound energy.

From the following statements find the one that is NOT correct:

physics the essence of change forms of energy and energy conservation energy for everything forms of energy

  1. A flying bird has both potential and kinetic energy.

  2. A ball rolling on the ground has kinetic energy but no mechanical energy.

  3. A stretched rubber band has potential energy

  4. Chemical energy can be converted into electrical energy

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Correct Option: B
Explanation:

A body having either. Kinetic' energy or Potential energy or both is said to be having Mechanical energy.