4 shampla de cheisteanna faoi theas sonrach agus acmhainn teasa
1. Cé acu a théamhnaíonn níos tapúla nuair a thriomaítear le chéile iad sa ghrian the, alúmanam nó copar? Is é teas sonrach alúmanaim = 900 J/kg o C agus is é teas sonrach copair = 390 J/kg o C.
Plé
Dá mhéad teas sonrach réada, is ea is faide a thógann sé ar an réad téamh suas, os a choinne sin, dá lú teas sonrach réada, is ea is tapúla a théamh sé suas.
Tá teas sonrach copair níos lú ná teas sonrach alúmanaim, dá bhrí sin téann copar suas níos tapúla.
2. Glacann réad a bhfuil mais 2 kg aige 100 calraí teasa nuair a athraíonn a theocht ó 20 o C go 70 o C. Is é teas sonrach an réada...
Plé
Is eol go:
Mais (m) = 2 kg = 2000 gr
Teas (Q) = 100 cal
Athrú teochta (ΔT ) = 70 o C – 20 o C = 50 o C
Ceist: Teas sonrach an réada (c)
Freagra:
c = Q / m ΔT
c = 100 cal / (2000 gr)(50 o C)
c = 100 cal / 100.000 gr o C
c = 102 cal / 105g o C
c = (102 cal )( 10-5 gr - 1 o C -1 )
c = 10-3 cal gr -1 o C -1
c = 10-3 cal/ gró de C
Is é teas sonrach an réada ná 10-3 cal /gr o C
3. Is é 4180 J/kg C₂ teas sonrach an uisce . Is é acmhainn teasa 2 kg uisce ná…..
Plé
Is eol go:
Teas sonrach uisce (c) = 4180 J/kg C o
Mais (m) = 2 kg
Ceist: Cumas teasa (C)
Freagra:
C = mc
C = (2 kg)(4180 J/kg C o )
C = (2)(4180 J/C o )
C = 8360 J/C o
4. Is é 900 J/kg C₂ teas sonrach alúmanaim . Is é acmhainn teasa 2 ghram alúmanaim…..
Plé
Is eol go:
Teas sonrach alúmanaim (c) = 900 J/kg C o = 9 x 10 2 J/kg C o
Mais (m) = 2 ghram = 2/1000 kg = 2/10³ kg = 2 x 10⁻³ kg
Ceist: Cumas teasa (C)
Freagra:
C = mc
C = (2 x 10 -3 kg)( 9 x 10 2 J/kg C o )
C = 18 x 10⁻³ x 10⁻² J / C₂
C = 18 x 10-1 J/C o
C = 1,8 J/C o
