★瘋狂丶

注意:  *等於-1 (小寫1)
第一條:A 3-kg metal block is heated to 100℃ and then put into a 5-kg water bath.
The temperature of the water bath rises from 27℃ to 31.7℃. What is the specific heat capacity of the metal block?
(specifi heat capacity of water=4200Jkg-* ℃-*)


第二條:
if 2kg of water at 80℃ is mixed with 5kg of water at 30℃, what is the final temperature of the 'mixture'?
(specifi heat capacity of water=4200Jkg-* ℃-*)


第三條:
The same amount of energy is transferred to an equal mass of water and copper.
which has a higher temperature rise, water or copper?
(the specifi heat capacities of water and copper are 4200Jkg-* ℃-* and 370 Jkg-* ℃-* respectively.)


第四條:
john is using a 200-W electric heater to heat 0.5kg of soup(Fig.c).What is the temperature of the soup after 5minutes if its initial temperature of is 20℃?
Assume all the energy given out by the electric heater is absorbed by the soup.
(specifi heat capacity of water=4200Jkg-* ℃-*)



麻煩你地希望可以詳細D  ><
因為月底都要測物理英文=.=`

[ 本帖最後由 ★瘋狂丶 於 2011-11-15 20:52 編輯 ]

♥_靈魂S

=.= 英文中學? 嘩物理甘難仲要英文 真係幫吾到你=.=

★瘋狂丶

引用:

原帖由 ♥_靈魂S 於 2011-11-15 20:47 發表
=.= 英文中學? 嘩物理甘難仲要英文 真係幫吾到你=.=

唔系英文中學黎- -`
系挑戰題  

紅白藍

31.+7℃ = =咩黎
如果係31度
水獲得既熱能:4x4200x4=67200J
鐵失去既熱能:3X(100-31)Xc
兩者相等
c=324Jkg-1C-1
第2條
兩者合埋總熱能:2x80x4200+5x30x4200=1302000J
加埋後有7kg水
1302000/7/4200=44.3度

[ 本帖最後由 紅白藍 於 2011-11-15 20:53 編輯 ]

★瘋狂丶

引用:

原帖由 紅白藍 於 2011-11-15 20:50 發表
31.+7℃ = =咩黎
如果係31度
水獲得既熱能:4x4200x4=67200J
鐵失去既熱能:3X(100-31)Xc
兩者相等
c=324Jkg-1C-1

唔系31度= =
我打錯
系31.7度有無得詳細D

紅白藍

引用:

原帖由 ★瘋狂丶 於 2011-11-15 20:51 發表
唔系31度= =
我打錯
系31.7度有無得詳細D

照將31.7度代番31度果個數= =無分別
無做熱學兩年..我都唔知岩唔岩

A_c

A 3-kg metal block is heated to 100℃ and then put into a 5-kg water bath.
The temperature of the water bath rises from 27℃ to 31.+7℃. What is the specific heat capacity of the metal block?
(specifi heat capacity of water=4200Jkg-* ℃-*)
紅字為唔明

if 2kg of water at 80℃ is mixed with 5kg of water at 30℃, what is the final temperature of the 'mixture'?
(specifi heat capacity of water=4200Jkg-* ℃-*)

2x4200x(80-T) =5X4200X(T-30)
=ANS.

The same amount of energy is transferred to an equal mass of water and copper.
which has a higher temperature rise, water or copper?
(the specifi heat capacities of water and copper are 4200Jkg-* ℃-* and 370 Jkg-* ℃-* respectively.)
知定義冇理由唔識




john is using a 200-W electric heater to heat 0.5kg of soup(Fig.c).What is the temperature of the soup after 5minutes if its initial temperature of is 20℃>
Assume all the energy given out by the electric heater is absorbed by the soup.
(specifi heat capacity of water=4200Jkg-* ℃-*)


p=e/t
p=q/t

200x5x60= m c /\t
好似應該係咁

[ 本帖最後由 A_c 於 2011-11-15 20:55 編輯 ]

★瘋狂丶

引用:

原帖由 A_c 於 2011-11-15 20:54 發表
A 3-kg metal block is heated to 100℃ and then put into a 5-kg water bath.
The temperature of the water bath rises from 27℃ to 31.+7℃. What is the specific heat capacity of the metal block?
(specifi ...

英文我真系好差,
年年英文都唔合格  =.=

A_c

ＰＨＹ呢啲英文好易姐，
我英文都係年年岩岩好合格多啲啲。

[ 本帖最後由 A_c 於 2011-11-15 21:00 編輯 ]

紅白藍

第4條
heater輸出熱能:200X5X60=60000J
60000= m c /\t
            =0.5(4200)/\t
      /\t  =28.6度
20+28.6=48.6度

★瘋狂丶

引用:

原帖由 A_c 於 2011-11-15 20:57 發表
ＰＨＹ呢啲英文好易姐，
我美文都係年年岩岩好合格多啲啲。

英文我都唔知可以點補救  
sad

A_c

引用:

原帖由 ★瘋狂丶 於 2011-11-15 21:00 發表
英文我都唔知可以點補救  
sad

好似應該由小學書睇番上去，
ｏｒ去圖書館借ｄ英文書睇。

Win:D

引用:

原帖由 A_c 於 2011-11-15 21:01 發表


好似應該由小學書睇番上去，
ｏｒ去圖書館借ｄ英文書睇。

老師真係勤力仲教你點讀英文  西利

★瘋狂丶

引用:

原帖由 A_c 於 2011-11-15 21:01 發表


好似應該由小學書睇番上去，
ｏｒ去圖書館借ｄ英文書睇。

我都希望會做到呢樣野=.=`
我又唔想日日比屋企人見到我溫書個個樣=.=`
日日系度諗呢樣,諗個樣..