Is this a Typo? | Quantity of Heat

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In summary, the question asks for the distance a 1.00kg block would have to fall to raise the temperature of 0.250kg of water from 20C to 90C. The answer from the book uses a temperature change of 70K and a heat transfer of 2.93x10^5J. However, there is a typo as the mass of the water should be 0.25kg, not 1kg. This would result in a different calculation for the distance the block would need to fall.
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sapiental
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This is one of those test your understanding questions out of the book.

What distance would a 1.00kg block have to fall to raise the temperature of .250kg of water from 20C to 90C? Assume that all potential emergy that the block loses as it falls goes into raising the emperature of the water?
(The system: the block is suspended by string through a pully and t attached to a axel. The axel has more thread wrapped around it and is attached to a horizontally rotating paddle inside a glass filled with water. so as the block falls the paddle is doing work on the water resulting in heat transfer Q. this is the most accurate description I can come up with from looking at the picture)This is the answer right out of the book:

The temperature change is T = 70K so the amount of heat is Q = (m_water)(c)(dT) = (1kg)(4190J/kgK)(70K) = 2.93x10^5J If the block falls a distance h, the amount of potential energy lost is m_block(g)(h), so h = Q/(m_block)(h) = (2.93e+10^5J)/(1.00kg)(9.8m/s^2) = 2.99^4 m
Is this a typo? They clearly distinguish m_water and m_block, yet they use 1kg for the mass of the water instead of .250kg. Or am I misunderstanding the question? I get Q = (.250)(c)(dt).
 
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  • #2
It's clearly a typo. You are right, the mass of the water should be 0.25 kg in the expression.
 
  • #3
thanks alot!
 

1. What is a typo?

A typo, short for typographical error, is a mistake or error made while typing or writing something. It can be a misspelled word, incorrect punctuation, or other errors that affect the accuracy or clarity of the text.

2. How can I tell if something is a typo?

The most common way to identify a typo is by proofreading the text for spelling or grammatical errors. Another way is by using spell check or grammar check tools, which can highlight potential typos in the text. Additionally, if a word or phrase seems out of place or makes the sentence difficult to understand, it could be a typo.

3. What is the quantity of heat?

The quantity of heat is a measure of the total amount of thermal energy in a system. It is typically measured in units of joules (J) or calories (cal) and is related to the temperature of the system.

4. How do I know if the quantity of heat is a typo?

If you are unsure whether the quantity of heat mentioned is correct, you can check the units to see if they are appropriate for the context. For example, if the quantity of heat is measured in grams (g), it is likely a typo as heat is typically measured in units of energy.

5. Are typos common in scientific writing?

Typos can occur in any type of writing, including scientific writing. However, due to the technical and precise nature of scientific writing, authors often take extra care to avoid typos. In addition, most scientific papers go through multiple rounds of editing and proofreading before being published, which can help catch and correct any typos.

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