What is the sample's specific heat?

The change in temperature is 20.0 degrees C, which is equivalent to 20 K. Also, be careful with your units. The weight of the sample is given in Newtons, but the formula for specific heat uses mass in kilograms. In summary, to determine the specific heat of a sample of metal, you must first convert the weight from Newtons to kilograms and the change in temperature from degrees Celsius to Kelvin. Then, using the formula Q=mc(delta)T, you can solve for c by substituting the given values and converting to the appropriate units.
  • #1
Arejang
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0

Homework Statement


You are given a sample of metal and asked to determine its specific heat. You weigh the sample and find that its weight is 30.0 N. You carefully add 1.30×10^4 J of heat energy to the sample and find that its temperature rises 20.0 degrees C.

What is the sample's specific heat?

Homework Equations



Q=mc (delta)T

The Attempt at a Solution



I solved for c giving:

c=Q/(m*(delta)T)

I converted the given degrees Celsius to Kelvin by adding 273.15, and converted the 30 Newtons to kg by dividing by 9.8 m/s^2. The resulting numbers, 293.15 was used for delta T, and 2.90 kg was used for m.

This was my resultant value and calculation prior to plug and chug:

1.30*10^4 J/(2.90 kg*293.15 K)

Plug and chug gave me 14.71 J/(kg*K). But it's not the correct answer. Could anyone show me what I did wrong?
 
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  • #2
293.15 K is not the change in temperature.
 
  • #3


Your calculation and approach seem correct. The specific heat of the sample is indeed 14.71 J/(kg*K). It is possible that the given answer is incorrect or that there was a mistake in the original problem. It is also possible that the sample is not a pure metal and has a different specific heat than expected. I would suggest checking with your instructor or a classmate to confirm the answer.
 

1. What is specific heat and why is it important?

Specific heat is the amount of heat required to raise the temperature of a substance by one degree Celsius. It is an important property because it helps us understand how much energy is needed to change the temperature of a material, and it can also be used to compare the heat capacities of different substances.

2. How is the specific heat of a sample measured?

The specific heat of a sample can be measured by using a calorimeter, which is a device that measures the heat exchanged between the sample and its surroundings. The sample is heated or cooled to a known temperature, and then placed in the calorimeter. The temperature change of the sample and the surrounding environment is then measured, and the specific heat can be calculated using the formula Q = mcΔT, where Q is the heat exchanged, m is the mass of the sample, c is the specific heat, and ΔT is the temperature change.

3. What factors can affect the specific heat of a sample?

The specific heat of a sample can be affected by its composition, temperature, and phase. Different substances have different specific heats, and the specific heat of a substance can also change depending on its temperature and whether it is a solid, liquid, or gas.

4. How does specific heat relate to heat capacity?

Specific heat and heat capacity are related, but not the same. Specific heat is a measure of the amount of heat needed to raise the temperature of a specific amount of material by one degree, while heat capacity is the amount of heat needed to raise the temperature of an entire system by one degree. The heat capacity of a system is equal to the product of its mass and specific heat.

5. How can knowledge of specific heat be applied in real-life situations?

Knowledge of specific heat is important in many real-life situations, such as in cooking, where different foods have different specific heats and require different amounts of heat to cook properly. It is also useful in industries that involve heating and cooling, as well as in understanding the Earth's climate and energy transfer processes.

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