Home
Class 11
PHYSICS
A metal ball immersed in alcohol weighs ...

A metal ball immersed in alcohol weighs `w_(1) " at" 0^(@)C " and" w_(2) " at " 59^(@)C`. The coefficient of cubical expansion of the metal is less than that of alcohol. Assuming that the density of the metal is large compared to that of alcohol, it can be shown that

A

`w_(1) gt w_(2)`

B

`w_(1)=w_(2)`

C

`w_(1) lt w_(2)`

D

`w_(1)=(w_(1)//2)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the behavior of a metal ball immersed in alcohol at two different temperatures, 0°C and 59°C. We will use the principles of buoyancy and thermal expansion to derive the relationship between the weights of the ball at these two temperatures. ### Step-by-Step Solution: 1. **Understanding the Apparent Weight**: - The apparent weight of the ball when immersed in a fluid is given by: \[ W_{\text{apparent}} = W_{\text{actual}} - F_{\text{upthrust}} \] - Here, \(W_{\text{actual}}\) is the actual weight of the ball, and \(F_{\text{upthrust}}\) is the upthrust force acting on the ball due to the displaced liquid. 2. **Calculating the Upthrust Force**: - The upthrust force can be expressed as: \[ F_{\text{upthrust}} = \text{Volume of the ball} \times \text{Density of the liquid} \times g \] - For a sphere, the volume is given by: \[ V = \frac{4}{3} \pi r^3 \] - Therefore, the upthrust force becomes: \[ F_{\text{upthrust}} = \frac{4}{3} \pi r^3 \rho_l g \] - Where \(\rho_l\) is the density of the liquid (alcohol) and \(g\) is the acceleration due to gravity. 3. **Case 1: At 0°C**: - Let the radius of the ball at 0°C be \(r_0\). - The upthrust force at 0°C is: \[ F = \frac{4}{3} \pi r_0^3 \rho_l g \] - Thus, the apparent weight \(W_1\) at 0°C can be expressed as: \[ W_1 = W_{\text{actual}} - F = W_{\text{actual}} - \frac{4}{3} \pi r_0^3 \rho_l g \] 4. **Case 2: At 59°C**: - As the temperature increases, the ball expands. The radius of the ball at 59°C can be expressed as: \[ r = r_0 (1 + \gamma_s \Delta T) \] - Where \(\gamma_s\) is the coefficient of cubical expansion of the metal, and \(\Delta T = 59 - 0 = 59\). - The density of the alcohol at 59°C decreases, which can be expressed as: \[ \rho_l' = \frac{\rho_l}{1 + \gamma_l \Delta T} \] - Where \(\gamma_l\) is the coefficient of cubical expansion of the liquid. 5. **Calculating the Upthrust Force at 59°C**: - The upthrust force at 59°C becomes: \[ F' = \frac{4}{3} \pi (r_0 (1 + \gamma_s \Delta T))^3 \rho_l' g \] - Substituting for \(\rho_l'\): \[ F' = \frac{4}{3} \pi (r_0 (1 + \gamma_s \Delta T))^3 \left(\frac{\rho_l}{1 + \gamma_l \Delta T}\right) g \] 6. **Comparing the Upthrust Forces**: - Since \(\gamma_s < \gamma_l\), the expansion of the alcohol is greater than that of the metal, leading to a decrease in upthrust force \(F'\) compared to \(F\). - Therefore, we can conclude that: \[ F' < F \] 7. **Determining the Apparent Weights**: - From the expressions for apparent weights: \[ W_2 = W_{\text{actual}} - F' \] - Since \(F' < F\), it follows that: \[ W_2 > W_1 \] ### Conclusion: Thus, we conclude that the weight of the metal ball at 59°C is greater than at 0°C: \[ W_2 > W_1 \]

To solve the problem, we need to analyze the behavior of a metal ball immersed in alcohol at two different temperatures, 0°C and 59°C. We will use the principles of buoyancy and thermal expansion to derive the relationship between the weights of the ball at these two temperatures. ### Step-by-Step Solution: 1. **Understanding the Apparent Weight**: - The apparent weight of the ball when immersed in a fluid is given by: \[ W_{\text{apparent}} = W_{\text{actual}} - F_{\text{upthrust}} ...
Promotional Banner

Topper's Solved these Questions

  • FLUID MECHANICS

    DC PANDEY ENGLISH|Exercise B) Medical entrance special format question|19 Videos
  • FLUID MECHANICS

    DC PANDEY ENGLISH|Exercise Match the columns|6 Videos
  • FLUID MECHANICS

    DC PANDEY ENGLISH|Exercise Check point 13.4|10 Videos
  • EXPERIMENTS

    DC PANDEY ENGLISH|Exercise Subjective|15 Videos
  • GENERAL PHYSICS

    DC PANDEY ENGLISH|Exercise INTEGER_TYPE|2 Videos

Similar Questions

Explore conceptually related problems

A metal ball immersed in alcohol weights W_1 at 0^@C and W_2 at 50^@C . The coefficient of expansion of cubical the metal is less than that of the alcohol. Assuming that the density of the metal is large compared to that of alcohol, it can be shown that

A metal ball immersed in water weighs w_(1) at 0^(@)C and w_(2) at 50^(@)C . The coefficient of cubical expansion of metal is less than that of water. Then

A metal ball immersed in water weighs w_(1) at 5^(@)C and w_(2) at 50^(@)C . The coefficient of cubical expansion of metal is less than that of water. Then

The volume of a block of a metal changes by 0.12% when it is heated through 20^(@)C . The coefficient of linear expansion of the metal is

A metal rod of silver of length 100cm at 0^(@)C is heated to 100^(@)C . It's length is increased by 0.19 cm . Coefficient of cubical expansion of the silver rod is

The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8. 9\ g\ p e r\ c m^3 ?

A metallic bar is heated from 0^(@)C to 100^(@)C . The coefficient of linear expansion is 10^(-5)K^(-1) . What will be the percentage increase in length

A metallic wire has a resistance of 3.0 Omega at 0^@C and 4.8 Omega at 150^@C . Find the temperature coefficient of resistance of its material.

A metal rod of length 100cm , made of silver at 0^(@)C is heated to 100^(@)C . It's length is increased by 0.19 cm . Coefficient of cubical expansion of the silver rod is

A clock with a metal pendulum beating seconds keeps correct time at 0^(@)C. If it loses 12.5s a day at 25^(@)C the coefficient of linear expansion of metal pendulum is

DC PANDEY ENGLISH-FLUID MECHANICS-Taking it together
  1. A sphere of mass m and radius r is projected in a gravity free space w...

    Text Solution

    |

  2. A wooden block of mass 8 kg is tied to a string attached to the bottom...

    Text Solution

    |

  3. A metal ball immersed in alcohol weighs w(1) " at" 0^(@)C " and" w(2) ...

    Text Solution

    |

  4. A barometer kept in an elevator reads 76 cm when it is at rest. If the...

    Text Solution

    |

  5. The surface energy of a liquid drop is E. It is sprayed into 1000 equa...

    Text Solution

    |

  6. An open tank containing non-viscous liquid to a height of 5 m is place...

    Text Solution

    |

  7. A large open tank has two holes in the wall. One is a square hole of s...

    Text Solution

    |

  8. A piece of steel has a weight w in air, w(1) when completely immersed ...

    Text Solution

    |

  9. Two cylinders of same cross-section and length L but made of two diffe...

    Text Solution

    |

  10. A block of wood is floating on the surface of water in a beaker. The b...

    Text Solution

    |

  11. A beaker containing water is kept on a spring scale. The mass of water...

    Text Solution

    |

  12. A sphere of solid material of specific gravity 8 has a concentric sphe...

    Text Solution

    |

  13. A cubical block of side 10 cm floats at the interface of an oil and wa...

    Text Solution

    |

  14. A liquid stands at the plane level in the U-tube when at rest. If area...

    Text Solution

    |

  15. A capillary tube is dipped in a liquid. Let pressure at point A,B and ...

    Text Solution

    |

  16. The volume of an air bubble becomes three times as it rises from the b...

    Text Solution

    |

  17. Water falls from a tap with A(0)=4 m^(2), A=1 m^(2) and h=2 m, then ve...

    Text Solution

    |

  18. A ball of relative density 0.8 falls into water from a height of 2 m. ...

    Text Solution

    |

  19. A pump is designed as a horizontal cylinder with a piston of area A an...

    Text Solution

    |

  20. If cross- sectional area of limb I is A(1) and that of limb II is A(2)...

    Text Solution

    |