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State if the following statement is true or false. Give a reason for your answer. Total energy of a system is always conserved, no matter what internal and external forces on the body are present.

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प्रश्न

State if the following statement is true or false. Give a reason for your answer. 

Total energy of a system is always conserved, no matter what internal and external forces on the body are present.

विकल्प

  • True

  • False

MCQ
सत्य या असत्य
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उत्तर

This statement is False.

Explanation:

Even though internal forces are in equilibrium and do not perform work on a body, it is the external forces that possess the capability to do work. Consequently, external forces can alter the energy state of a system.

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अध्याय 5: Work, Energy and Power - EXERCISES [पृष्ठ ८९]

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एनसीईआरटी Physics [English] Class 11
अध्याय 5 Work, Energy and Power
EXERCISES | Q 5.7 (b) | पृष्ठ ८९

संबंधित प्रश्न

The rate of change of total momentum of a many-particle system is proportional to the ______ on the system.


State if the following statement is true or false. Give a reason for your answer.

In an elastic collision of two bodies, the momentum and energy of each body is conserved.


State if the following statement is true or false. Give a reason for your answer.

In an inelastic collision, the final kinetic energy is always less than the initial kinetic energy of the system.


Answer carefully, with reason:

In an inelastic collision of two billiard balls, is the total kinetic energy conserved during the short time of collision of the balls (i.e., when they are in contact)?


A bullet of mass 0.012 kg and horizontal speed 70 m s–1 strikes a block of wood of mass 0.4 kg and instantly comes to rest with respect to the block. The block is suspended from the ceiling by means of thin wires. Calculate the height to which the block rises. Also, estimate the amount of heat produced in the block.


Define coefficient of restitution.


Answer the following question.

Discuss the following as special cases of elastic collisions and obtain their exact or approximate final velocities in terms of their initial velocities.

  1. Colliding bodies are identical.
  2. A very heavy object collides on a lighter object, initially at rest.
  3. A very light object collides on a comparatively much massive object, initially at rest.

Solve the following problem.

A spring ball of mass 0.5 kg is dropped from some height. On falling freely for 10 s, it explodes into two fragments of mass ratio 1:2. The lighter fragment continues to travel downwards with a speed of 60 m/s. Calculate the kinetic energy supplied during the explosion.


Two different unknown masses A and B collide. A is initially at rest when B has a speed v. After collision B has a speed v/2 and moves at right angles to its original direction of motion. Find the direction in which A moves after the collision.


A ball is thrown vertically down from height of 80 m from the ground with an initial velocity 'v'. The ball hits the ground, loses `1/6`th of its total mechanical energy, and rebounds back to the same height. If the acceleration due to gravity is 10 ms-2, the value of 'v' is


A block of mass 'm' moving on a frictionless surface at speed 'v' collides elastically with a block of same mass, initially at rest. Now the first block moves at an angle 'θ' with its initial direction and has speed 'v1'. The speed of the second block after collision is ______.


A mass M moving with velocity 'v' along x-axis collides and sticks to another mass 2M which is moving along Y-axis with velocity 3v. After collision, the velocity of the combination is ______.


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A smooth sphere of mass 'M' moving with velocity 'u' directly collides elastically with another sphere of mass 'm' at rest. After collision, their final velocities are V' and V respectively. The value of V is given by ______.


During inelastic collision between two bodies, which of the following quantities always remain conserved?


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In a collision, what type of interaction occurs between objects?


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