Home
Class 11
PHYSICS
Assertion : Work done by friction on a...

Assertion : Work done by friction on a body sliding down an inclined plane is positive. Reason : Work done is greater than zero, if angle between force and displacement is acute or both are in same direction.

A

If both assertion and reason are true and the reason is the correct explanation of the assertion.

B

If both assertion and reason are true but reason is not the correct explanation of the assertion.

C

If assertion is true but reason is false.

D

If assertion is false but reason is true.

Text Solution

Verified by Experts

The correct Answer is:
D
Work (W) by friction is -ve because it opposes motion if `theta lt 90^@ rarr W = F .s. cos theta rarr W rarr (+ve)`
[F and S same direction].
Promotional Banner

Topper's Solved these Questions

  • WORK, ENERGY POWER AND COLLISION

    ERRORLESS|Exercise PAST YEARS QUESTIONS|26 Videos

  • WAVES AND SOUND

    ERRORLESS|Exercise ASSERTION & REASON |25 Videos

Similar Questions

Explore conceptually related problems

If the work done is zero, then the angle between the force and displacement is

Maximum work will be done if the angle between force applied and displacement produced is

Assertion : When the force retards the motion of a body, the work done is zero. Reason : Work done depends on angle between force and displacement.

Assertion: Work done by the force of friction in moving a body around a closed loop is zero. Reason: Work done does not depend upon the nature of force.

Derive an expression for the work done when a body slides down a rough inclined plane.

Work done by a force in displacing a body is an example of

ERRORLESS-WORK, ENERGY POWER AND COLLISION-ASSERTION & REASON
  1. Assertion : If two protons are brought near one another, the potential...

    Text Solution

    |

  2. Assertion: Mass and energy are not conserved separately, but are conse...

    Text Solution

    |

  3. Assertion : Work done by friction on a body sliding down an inclined...

    Text Solution

    |

  4. Assertion : When a gas is allowed to expand, work done by gas is pos...

    Text Solution

    |

  5. Assertion: A light body and a heavy body have same momentum. Then they...

    Text Solution

    |

  6. Assertion : Mountain roads rarely go straight up the slope. Reason ...

    Text Solution

    |

  7. Assertion: The change in kinetic energy of a particle is equal to the ...

    Text Solution

    |

  8. Assertion: A spring has potential energy , both when it is compressed ...

    Text Solution

    |

  9. Assertion : Comets move around the sun in elliptical orbits. The gravi...

    Text Solution

    |

  10. Assertion : The rate of change of total momentum of a many particle sy...

    Text Solution

    |

  11. Assertion : A work done in moving a body over a closed loop is zero ...

    Text Solution

    |

  12. Assertion: Power of machine gun is determined by body both the number ...

    Text Solution

    |

  13. Assertion: According to law of conservation of machainical energy chan...

    Text Solution

    |

  14. Assertion : When the force retards the motion of a body, the work do...

    Text Solution

    |

  15. Assertion: In an elastic collision of two bodies , the momentum and en...

    Text Solution

    |

  16. Assertion : In case of bullet fired from gun, the ratio of kinetic e...

    Text Solution

    |

  17. Assertion : Power developed in circular motion is always zero. Rea...

    Text Solution

    |

  18. Assertion : A kinetic energy of a body is quadrupled, when its veloc...

    Text Solution

    |

  19. Assertion: A quick collisions between two bodies is more violent than ...

    Text Solution

    |

  20. Assertion : Work done by or against gravitational force in moving a b...

    Text Solution

    |