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Substance Specific Heat (J kg-1 K-1) Aluminum 900 Copper 390 Brass 380 Silver 230 Platinum 130 If 130 J of energy were added to 1 kg of each of these samples, which would experience the GREATEST temperature increase? A) Aluminum B) Brass C) Copper D) Platinum

Respuesta :

Answer:

Choice D) Platinum.

Explanation:

The specific heat of a substance gives the amount of energy it takes to raise the temperature of

  • unit mass (1 kilogram in this case) of the substance,
  • by one unit (1 degree Kelvin in this case).

After energy of size [tex]Q[/tex] is added to a sample with specific heat [tex]c[/tex] and mass [tex]m[/tex], the temperature change would be:

[tex]\Delta T = \displaystyle \frac{Q}{c \cdot m}[/tex].

For each of these samples, [tex]Q = 130\; \rm J[/tex], [tex]m = 1\; \rm kg[/tex]. Apply this equation to find the change in their temperatures.

Aluminum

[tex]c = \rm 900\; \rm J \cdot kg^{-1}\cdot K^{-1}[/tex].

[tex]\begin{aligned}\Delta T &= \frac{Q}{c \cdot m} \\ &= \frac{130\; \rm J}{900\; \rm J \cdot kg^{-1} \cdot K^{-1}} \approx 0.14\; \rm K\end{aligned}[/tex].

Copper

[tex]c = 390\; \rm J \cdot kg^{-1}\cdot K^{-1}[/tex].

[tex]\begin{aligned}\Delta T &= \frac{Q}{c \cdot m} \\ &= \frac{130\; \rm J}{390\; \rm J \cdot kg^{-1} \cdot K^{-1}} \approx 0.33\; \rm K\end{aligned}[/tex].

Brass

[tex]c = 380\; \rm J \cdot kg^{-1}\cdot K^{-1}[/tex].

[tex]\begin{aligned}\Delta T &= \frac{Q}{c \cdot m} \\ &= \frac{130\; \rm J}{380\; \rm J \cdot kg^{-1} \cdot K^{-1}} \approx 0.34\; \rm K\end{aligned}[/tex].

Silver

[tex]c = 230\; \rm J \cdot kg^{-1}\cdot K^{-1}[/tex].

[tex]\begin{aligned}\Delta T &= \frac{Q}{c \cdot m} \\ &= \frac{130\; \rm J}{230\; \rm J \cdot kg^{-1} \cdot K^{-1}} \approx 0.57\; \rm K\end{aligned}[/tex].

Platinum

[tex]c = 130\; \rm J \cdot kg^{-1}\cdot K^{-1}[/tex].

[tex]\begin{aligned}\Delta T &= \frac{Q}{c \cdot m} \\ &= \frac{130\; \rm J}{130\; \rm J \cdot kg^{-1} \cdot K^{-1}} \approx 1.0\; \rm K\end{aligned}[/tex].

Hence, platinum would experience the greatest temperature increase.

Answer:

D) Platinum

Explanation:

I agree