Home
Class 11
PHYSICS
(i) The cause of increases in kinetic en...

(i) The cause of increases in kinetic energy when a man starts running without his feet slipping on ground is asked to two students. Their answers are– Harshit: Cause of increase in kinetic energy is work done by friction force. Without friction the man cannot run. Akanksha: Cause of increase in kinetic energy is work done by internal (muscle) forces of the body. Who is right? (ii) An inextensible rope is hanging from a tree. A monkey, having mass m, climbs to a height h grabbing the rope tightly. The monkey starts from rest and ends up hanging motionlessly on the rope at height h. (a) How much work is done by gravity on the monkey? (b) How much work is done by the rope on the monkey? (c) Using work – energy theorem, explain the increase in mechanical energy of the monkey.

Text Solution

Verified by Experts

The correct Answer is:
(i) Akanksha is right. (ii) a -mgh
(b) 0
(c) Internal (muscle) forces of the body perfom work
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

Work done by kinetic friction can be

Work done by a frictional force is

Knowledge Check

  • Work done by frictional force

    A
    Is always negative
    B
    Is always positive
    C
    Is zero
    D
    May be positive, negative or zero

  • Work done by the force of friction

    A
    can be zero
    B
    can be positive
    C
    can be negative
    D
    any of the above

  • Kinetic energy of a body rolling without slipping is

    A
    `K = (1)/(2) mv^(2)`
    B
    `K = (1)/(2) I omega^(2)`
    C
    `K = (1)/(2)mv^(2) + (1)/(2) I omega^(2)`
    D
    `K = (1)/(2)mv^(2) - (1)/(2)I omega^(2)`

    • Similar Questions

    Explore conceptually related problems

    The work done by kinetic friction on a body :

    If kinetic energy of a body is increasing then.

    The increase in kinetic energy for a body whose increase in linear momentum is 50% will be

    If the increase in the kinetic energy of a body is 22%, then the increase in the momentum will be

    If the increase in the kinetic energy of a body is 22%, then the increase in the momentum will be

    Home
    Profile