9 Mais Teasa Teas Sonrach An t-athrú teochta – Fadhbanna agus Réitigh
1. Téitear luaidhe 2 kg ó 50oC go 100oC. Tá an teas sonrach luaidhe is ea 130 J.kg-1 oC-1. Cé mhéad a teasa an bhfuil an luaidhe ag ionsú?
Ar a dtugtar:
Mais (m) = 2 kg
An teas sonrach (c) = 1 3 0 J.kg -1 C -1
An t-athrú teochta ( ΔT ) = 100 o C – 50 o C = 50 o C
Ag Teastáil: Teas (Q)
Réiteach:
Q = mc ΔT
Q = teas , m = mais, c = an teas sonrach , ΔT = an t-athrú teochta
An teas a ionsúnn luaidhe:
Q = (2 kg)(1 3 0 J.kg -1 C -1 )(50 ° C)
Q = (100)(1 3 0)
Q = 1 3,000 Giúl
Q = 1.3 x 104 Giúl
[irp]
2. Is é 390 J/k g o C teas sonrach copair , is é 40 o C an t-athrú teochta. Má ionsúnn an copar 40 Giúl teasa, cad é mais an chopair!
Ar a dtugtar:
Teas sonrach copair (c) = 390 J/k g o C
An t-athrú teochta ( ΔT ) = 40 ° C
Teas ( Q) = 40 J
Ag Teastáil: Mais (m) copair
Réiteach:
Q = mc ΔT
40 J = (m)( 390 J/k g o C)(40 o C)
40 = (m)( 390 /k g)(40)
40 = (m)( 390 /kg )(4)
40 = (m)( 1560 /kg )
m = 40 / 1560
m = 0.026 kg
m = 26 gram
3. Is é 30 o C teocht tosaigh 20 gram uisce. Is é 1 cal g -1 o C -1 teas sonrach an uisce . Má ionsúnn uisce 300 calraí teasa, faigh amach an teocht deiridh!
Ar a dtugtar:
Mais (m) = 20 gr
An teocht tosaigh (T1 ) = 30 ° C
Teas sonrach an uisce (c) = 1 cal gr -1 o C -1
Teas (Q) = 300 cal
Ag Teastáil: Teocht deiridh an uisce
Réiteach:
Q = mc ΔT
300 cal = (20 gr)( 1 cal gr -1 o C -1 )( T 2 -30 )
300 = (20)(1) ( T2-30 )
300 = 20 ( T2-30 )
300 = 20 T2 – 600
300 + 600 = 20T2
900 = 20T2
T2 = 900 / 20
T2 = 45
Is é an t-athrú teochta ná 45 o C – 30 o C = 15 o C.
[irp]
4. Tan t-athrú teochta den uisce farraige is 1oC nuair a ionsúnn uisce 3900 Giúl teasa. Is é teas sonrach uisce na farraige 3.9 10 ×3 J/kg°C, cad é mais uisce na farraige.
Ar a dtugtar:
An t-athrú teochta ( ΔT ) = 1 ° C
Teas (Q) = 3900 Giúl
Teas sonrach uisce na farraige (c) = 3.9 x 10³ J / k g°C = 3900 J/Kg°C
Ag Teastáil: Mais (m)
Réiteach:
Q = mc ΔT
Q = teas , m = mais, c = teas sonrach , ΔT = an t-athrú teochta
m = Q / c ΔT = 3900 / (3900)(1) = 3900 / 3900 = 1 kg
5. Glacann copar 2 kg 39,000 J teasa ag 30°C. Más é teas sonrach copair 390 J/kg °C, cad é teocht deiridh an chopair …
Ar a dtugtar:
Mais (m) = 2 kg
Teocht tosaigh (T1 ) = 30 ° C
Teas (Q) = 39,000 Giúl
Teas sonrach (c) copair = 390 J/kg o C
Ag Teastáil : An teocht deiridh ( T2 )
Réiteach:
Q = mc ΔT
Q = teas , m = mais, c = teas sonrach , ΔT = an t-athrú teochta
Q = mc² ΔT = mc² ( T² – T¹ )
39,000 = (2)( 390)(T2 – 30)
100 = (2)(1)(T2 – 30)
100 = (2)(T2 – 30)
50 = T2 – 30
T2 = 50 + 30
T2 = 80 ° C
[irp]
6. Téitear uisce 5 kg ó 15°C go 40°C. Cad é an teas a ionsúnn an t-uisce? Is é teas sonrach uisce 4.2 × 10³ J /Kg°C.
Ar a dtugtar:
Mais (m) = 5 kg
Teocht tosaigh (T1 ) = 15°C
Teocht deiridh (T2 ) = 40°C
Teas sonrach uisce (c) = 4.2 × 10³ J /kg° C
Ag Teastáil: Teas (Q)
Réiteach:
Q = mc ΔT
Q = (5 kg)( 4.2 × 10³ J /kg°C)(40°C – 15°C)
Q = (5)( 4.2 × 10³ J )(25)
Q = 525 x 10³ J
Q = 525,000 Giúl
7. Téitear uisce 2 kg ó 24°C go 90°C. Cad é an teas a ionsúnn an t-uisce? Is é teas sonrach uisce 4.2 × 10³ J /Kg°C.
Ar a dtugtar:
Mais (m) = 2 kg
Teocht tosaigh (T1 ) = 24°C
Teocht deiridh (T2 ) = 90°C
Teas sonrach uisce (c) = 4,200 Giúl/kg°C
Ag Teastáil :: Teas (Q)
Réiteach:
Q = m c ΔT
Q = (2 kg)( 4,200 Giúl/kg°C)(90°C – 24°C)
Q = (2 kg)( 4,200 Giúl/kg°C)(66°C)
Q = (132)( 4,200 Giúl)
Q = 554,400 Giúl
[irp]
8. Téitear uisce 5 ghram ó 10°C go 40°C. Cad é an teas a ionsúnn an t-uisce? Is é teas sonrach uisce 1 × 10³ cal / g r °C.
Ar a dtugtar:
Mais (m) = 5 ghram
Teocht tosaigh (T1 ) = 10 ° C
Teocht deiridh (T2 ) = 40 ° C
Teas sonrach uisce (c) = 1 c al/ gr°C
Ag Teastáil : Teas
Réiteach:
Q = mc ΔT
Q = (5 gram)( 1 cal/gr°C)(40 ° C – 10 ° C)
Q = (5)( 1 c al)(30)
Q = 150 calraí
9. Glacann uisce 0.2 kg 42,000 Giúl teasa ag 25 o C. Is é teas sonrach an uisce ná 4200 J/kg o C, agus is é sin teocht deiridh an uisce.
Ar a dtugtar:
Mais uisce (m) = 0.2 kg
Teas (Q) = 42,000 Giúl
Teas sonrach uisce (c) = 4200 J/kg o C
Teocht tosaigh (T1 ) = 25 ° C
Ag Teastáil: Teocht Deiridh ( T2 )
Réiteach:
Q = mc² ΔT = mc² ( T² – T¹ )
Q= teasa, m = mais, c = teas sonrach, ΔT = an t-athrú teochta, T1 = an teocht tosaigh, T2 = an teocht deiridh
Q = mc( T2 – T1 )
42,000 = (0.2)(4200)(T2 – 25)
42,000 = 840 (T2 – 25)
42,000 = 840 T2 – 21,000
42,000 + 21,000 = 840 T²
63,000 = 840 T2
T2 = 63,000 / 840
T2 = 75 ° C
- Scálaí teochta a thiontú
- Leathnú líneach
- Leathnú ceantair
- Leathnú toirte
- Teas
- Coibhéis mheicniúil teasa
- Teas sonrach agus acmhainn teasa
- Teas folaigh, teas comhleá, teas galúcháin
- Caomhnú fuinnimh le haghaidh aistriú teasa
