मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान इयत्ता ११

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.

Advertisements
Advertisements

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.

पर्याय

  • True

  • False

MCQ
चूक किंवा बरोबर
Advertisements

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.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 5: Work, Energy and Power - EXERCISES [पृष्ठ ८९]

APPEARS IN

एनसीईआरटी Physics Part 1 and 2 [English] Class 11
पाठ 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:

Is the total linear momentum conserved during the short time of an elastic collision of two balls?


A molecule in a gas container hits a horizontal wall with speed 200 m s–1 and angle 30° with the normal, and rebounds with the same speed. Is momentum conserved in the collision? Is the collision elastic or inelastic?


Two identical ball bearings in contact with each other and resting on a frictionless table are hit head-on by another ball bearing of the same mass moving initially with a speed V. If the collision is elastic, which of the following figure is a possible result after collision?


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 ball of mass 100 g dropped on the ground from 5 m bounces repeatedly. During every bounce, 64% of the potential energy is converted into kinetic energy. Calculate the following:

  1. Coefficient of restitution.
  2. The speed with which the ball comes up from the ground after the third bounce.
  3. The impulse was given by the ball to the ground during this bounce.
  4. Average force exerted by the ground if this impact lasts for 250 ms.
  5. The average pressure exerted by the ball on the ground during this impact if the contact area of the ball is 0.5 cm2.

What is inelastic collision? In which way it is different from an elastic collision. Mention a few examples in day-to-day life for inelastic 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 ball of mass 0.1 kg makes an elastic head-on collision with a ball of unknown mass, initially at rest. If the 0 .1 kg ball rebounds at one-third of its original speed, the mass of the other ball is ______.


A wooden block of mass 'M' moves with velocity 'v ' and collides with another block of mass '4M' which is at rest. After collision, the block of mass 'M' comes to rest. The coefficient of restitution will be ______.


A block of mass 'm' moving along a straight line with constant velocity `3vec"v"` collides with another block of same mass at rest. They stick together and move with common velocity. The common velocity is ______.


Two bodies of masses 3 kg and 2 kg collide bead-on. Their relative velocities before and after collision are 20 m/s and 5 m/s respectively. The loss of kinetic energy of the system is ______.


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


An alpha-particle of mass m suffers 1-dimensional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing, 64% of its initial kinetic energy. The mass of the nucleus is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×