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A lead ball at 30^@C is dropped from a h...

A lead ball at `30^@C` is dropped from a height of `6.2km`. The ball is heated due to the air resestance and it completely melts just before reaching the ground. The molten substance falls slowly on the ground. Calculate the latent heat of fusion of lead. Specific heat capacity of lead `=126 J//Kg-^(@)C` and the melting point of lead `=330^@C`. Assume that any mechanical energy lost is used to heat the ball.

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Loss in mechanical energy `=`Heat
`mgh=msDeltatheta+mL`
`10xx6.2xx10^3=126xx(330-30)+L`
`L=62xx10^3-37.8xx10^3`
`=25.2xx10^3 J//kg`
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A lead ball at 30^(@)C is dropped from a height h. The ball is heated due to the air resistance and it completely melts just before reaching the ground, The molten substance falls slowly on the ground. Latent heat of fusion of lead is 22200 Jk//g . Specific heat capacity of lead =126J//kg-^(@)C and melting point of lead =330^(@)C , Assume that all mechanical energy lost is used to heat the ball. Find the value of h in km ? ("Use" g=10 m//s2)

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CP SINGH-HEAT AND CALORIMETRY-Exercise
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  2. Heat and work are equivalent i.e.,

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  3. The temperature of an object is observed to rise in a period. In this ...

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  4. If heat is supplied to s solid its temperature (i) must increase (...

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  5. The temperature of a solid object is observed to be constant during a ...

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  6. If specific heat of a substance is infinite, it means

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  7. Boiling water is changing into steam. Under this condition the specifi...

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  8. Calorie is defined as the amount of heat required to raise temperature...

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  9. A metallic ball and highly stretched spring are made of the same mater...

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  10. A 50 kg man is running at a speed of 18 kmH^(-1) If all the kinetic en...

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  11. A ball is dropped on a floor from a height of 2.0m. After the collisio...

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  12. A lead bullet strikes against a steel plate with a velocity 200ms^-1. ...

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  13. A lead bullet penetrates into a solid object and melts. Assuming that ...

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  14. An electric kettle takes 4 A current at 220 V. How much time will it t...

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  15. Hailstone at 0^@C from a height of 1 km on an insulating surface conve...

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  16. Two bodies at different temperature are mixed in a calorimeter.Which o...

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  17. A liquid of mass m and specific heat c is heated to a temperature 2T. ...

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  18. Two liquids A and B are at 30^@C and 20^@C, respectively When they are...

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  19. A vessel contains 110 g of water. The heat capacity of the vessel is e...

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  20. The temperature of equal masses of three different liquids A, B and C ...

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  21. Heat is supplied to a certain homogeneous sample of matter, at a unifo...

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