Home
Class 11
PHYSICS
A man whose mass is 50 kg climbs up 20 s...

A man whose mass is 50 kg climbs up 20 steps of the stairs with mass of 20 kg on his head .If each step of stair is `0.25` m in height , then work done by a man will be `………`

A

475 J

B

3500 J

C

1715 J

D

3430 J

Text Solution

Verified by Experts

The correct Answer is:
D
Total mass m = mass of man + mass on head
` = 50 +20`
` = 70 kg `
Height increases = height of one step `xx` total no of steps ,
` = 0.25 xx20`
` = 5 m `
` :.` Work W = change in potential energy
= mgh
` = 70 xx 9.8 xx 5`
= 3430 J
Promotional Banner

Topper's Solved these Questions

  • WORK, ENERGY AND POWER

    KUMAR PRAKASHAN|Exercise QUESTION PAPER (SECTION - A)|6 Videos

  • WORK, ENERGY AND POWER

    KUMAR PRAKASHAN|Exercise QUESTION PAPER (SECTION - B)|2 Videos

  • WORK, ENERGY AND POWER

    KUMAR PRAKASHAN|Exercise SECTION - E Multiple Choice Questions (MCQs)|64 Videos

  • WAVES

    KUMAR PRAKASHAN|Exercise SECTION-F (Questions From Module) (Sample questions for preparation of competitive exams)|23 Videos

Similar Questions

Explore conceptually related problems

Hetal having mass 50 kg climbs up 20 m height with an object of mass 30 kg for 40 s, then her power is …………… W. (Take g=10ms^(-2) )

A boy of mass 50 kg runs up a staircase of 45 steps in 9 s. If the height of each step in 15 cm, find his power. Take g=10ms^(-2) .

A man of mass m , standing at the bottom of the staircase of height L climbs it and stands at its top .

A man pulls a bucket of water from a depth of h from a well. If the mass of the rope and that of bucket full of water are m and M respectively, the work done by the man is :

A man whose mass is m kg jumps vertically into air from a sitting position in which his centre of mass is at a height h_(1) from the ground. When his feet are just about to leave the ground his centre of mass is h_(2) from the ground and finally rises to h_(3) when he is at top of the jump . What is the average upwards force exerted by the ground on him ?

A boy of mass 40 kg climbs a staircase of 30 steps, each of 0.2 m height, in 30 s. Calculate power. (g=9.8ms^(-2))

Calculate the power of a crane in watts, which lifts a mass of 100 kg to a height of 10 m in 20 s.

KUMAR PRAKASHAN-WORK, ENERGY AND POWER -SECTION - F Questions From Module (Sample questions for preparation of competitive exams)
  1. A particle fall freely from height s . At certain height its kinetic ...

    Text Solution

    |

  2. A body of mass 3 kg fall freely from the building of height 60 m . ...

    Text Solution

    |

  3. A mass of 0.5 kg moving with a speed of 1.5 m/s on a horizontal smooth...

    Text Solution

    |

  4. inelastic collision of two sphere of right body ………

    Text Solution

    |

  5. Two bodies of mass 1 g and 4 g moving with equal kinetic energy then ...

    Text Solution

    |

  6. How much work done in pulling up a block of wood weighing 2kN for leng...

    Text Solution

    |

  7. The kinetic energy of a body becomes four times its intial value , the...

    Text Solution

    |

  8. An electron , a proton a deutron and alpha - particle have the same k...

    Text Solution

    |

  9. If a body of mass 100 kg takes hight 60 m in 1 minute how much power i...

    Text Solution

    |

  10. An engine delivered power of 30 kW to a car of mass 1250 kg and veloci...

    Text Solution

    |

  11. Which one of the following force is non- conservative ?

    Text Solution

    |

  12. A body of mass 1 kg is thrown upwards with a velocity 20 ms^(-1) .It m...

    Text Solution

    |

  13. If the kinetic energy of the body is increased by 300 % then , the in...

    Text Solution

    |

  14. A car of mass m is driven with acceleration 'a' along a staright leve...

    Text Solution

    |

  15. A man whose mass is 50 kg climbs up 20 steps of the stairs with mass o...

    Text Solution

    |

  16. A sphere of mass 2 kg moving at 36 km/hr collides head on with anothe...

    Text Solution

    |

  17. Two bodies of masses m(1) and m(2) have same linear momentum . The rat...

    Text Solution

    |

  18. An elastic balls falls from a height of 10 m . If lose 80 % of its to...

    Text Solution

    |

  19. A ball moving with velocity 2m/s collides head on with another station...

    Text Solution

    |

  20. A bullet is fired from agun . If it recoils freely then kinetic energy...

    Text Solution

    |