Course: 9.3 特定热量 | The Way To Learn

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特定热热

This image is of the Beehive Geyser in Yellowstone National Park. Underground water is heated by the earth’s molten core and, when sufficient pressure is built up, the water shoots out of the ground in an amazing display.
::这是黄石公园的Beehive Geyser(Beehive Geyser)的图像。地下水被地球的熔化岩芯所加热,当足够的压力积聚起来,水就会在惊人的展示中从地上喷出。

Specific Heat
::特定热热

When flows into an object, its increases and so does its . The amount of temperature increase depends on three things: 1) how much heat was added, 2) the size of the object, and 3) the material of which the object is made. When you add the same amount of heat to the same mass of different substances, the amount of temperature increase is different. Each substance has a specific heat, which is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
::当向一个物体流动时,温度上升量会增加。温度上升量取决于三件事:1) 加热多少,2) 物体大小,3) 物体的制造材料。当在不同物质相同质量上添加相同数量的热时,温度上升量是不同的。每种物质都有特定的热量,即用一个温度单位将物质的一个质量单位提升到一个质量单位所需的热量。

In the SI system, specific heat is measured in J/kg•K. (Occasionally, you may also see specific heat expressed sometimes in J/g•K). The specific heat of aluminum is 903 J/kg•K. Therefore, it requires 903 J to raise 1.00 kg of aluminum by 1.00 K.
::在SI系统中,用J/kg/K.K.测量特定热量(从实际角度看,你还可以看到J/g/K.K.有时以J/g/K.K.表示的特定热量)。铝的具体热量为903 J/kkk.K.。因此,它要求903 J将1.00千克的铝增加1.00K.。

Specific Heat of Some Common Substances
Material	Specific Heat (J/kg•K)
Aluminum	903
Brass	376
Carbon	710
Copper	385
Glass	664
Ice	2060
Lead	130
Methanol	2450
Water Vapor	2020
Water (liquid)	4180
Zinc	388

The amount of heat gained or lost by an object when its temperature changes can be calculated by the formula
::当一个物体的温度变化可以用公式计算时,该物体获得或损失的热量

$\begin{aligned} Q = m c Δ T \end{aligned}$ ,
::T,

where $\begin{aligned} Q \end{aligned}$ is the heat gained or lost, $\begin{aligned} m \end{aligned}$ is the mass of the object, $\begin{aligned} c \end{aligned}$ is its specific heat, and $\begin{aligned} Δ T \end{aligned}$ is the change in temperature. You should note that the size of a Celsius degree and a Kelvin degree are exactly the same, and therefore $\begin{aligned} Δ T \end{aligned}$ is the same whether measured in Celsius or Kelvin.
::当 Q 是热增或损时, m 是对象的质量, c 是其特定的热, 和 T 是温度的变化。您应该注意 , 摄氏度和开尔文度的大小完全相同 , 因此 T 是以摄氏度或开尔文计量的相同。

Examples
::实例

Example 1
::例1

A 0.500 kg block of zinc is heated from 295 K to 350. K. How much heat was absorbed by the zinc?
::一个0.500千克的锌块从295K加热到350K。 K. 锌吸收了多少热量?

$\begin{aligned} Q = m c Δ T = (0.500 k g) (388 J / k g \cdot K) (350. K - 295 K) = 10, 600 J \end{aligned}$
::mcT=(0.500公斤)(388 J/kgK)(350.K-295 K)=10,600 J

Example 2
::例2

845 J of heat are added to a 0.200 kg block of aluminum at a temperature of 312.00 K. How high will the temperature of the aluminum rise?
::845 J热加到0.200公斤铝块中,温度为312.00K。铝的温度会升到多高?

$\begin{aligned} (T_{2} - T_{1}) = \frac{Q}{m c} = \frac{845 J}{(0.200 k g) (903 J / k g \cdot K)} = 4.68 K \end{aligned}$
:T2-T1)mc=845 J(0.200公斤)(903 J/kgK)=4.68K

$\begin{aligned} T_{2} = T_{1} + 4.68 K = 312.00 K + 4.68 K = 316.68 K \end{aligned}$
::T2=T1+4.68 K=312.00 K+4.68 K=316.68 K

Try to determine the identity of each unknown substance using specific heat in the PLIX Interactive below:
::尝试在下面的 PLIX 互动中使用特定的热量确定每种未知物质的身份 :

Summary
::摘要

When heat flows into an object, its thermal energy increases and so does its temperature.
::当热流入物体时,其热能会增加,温度也会增加。

The amount of temperature increase depends on three things: 1) how much heat was added, 2) the size of the object, and 3) the material of which the object is made.
::温度升高的幅度取决于三件事1) 加热多少,(2) 物体大小,(3) 制造物体的材料。

Each substance has a specific heat, which is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
::每种物质都有特定的热量,即用一个温度单位将一种物质的一个质量单位升到一个温度单位所需的热量。

The amount of heat gained or lost by an object when its temperature changes can be calculated by the formula $\begin{aligned} Q = m c Δ T \end{aligned}$ .
::当一个物体的温度变化可以用公式 mcT计算时,该物体的热量增减。

Review
::回顾

How much heat is absorbed by 60.0 g of copper when it is heated from 20.0°C to 80.0°C?
::在20.0摄氏度至80.0摄氏度之间加热时,60.0克铜吸收的热量是多少?

A 40.0 kg block of lead is heated from -25°C to 200.°C. How much heat is absorbed by the lead block?
::40.0千克铅块从 -25°C加热到200°C。铅块吸收了多少热量?

The cooling system of an automobile motor contains 20.0 kg of water. What is the $\begin{aligned} Δ T \end{aligned}$ of the water if the engine operates until 836,000 J of heat have been added to the water?
::汽车发动机的冷却系统装有20.0公斤的水,如果发动机一直运转到83.6万焦耳热量被添加到水中,水的温度是多少?

Section outline

General

特定热热

Specific Heat ::特定热热

Examples ::实例

Example 1 ::例1

Example 2 ::例2

Summary ::摘要