Mienzaniso mishanu yezvinetso zvekupisa
1. Tin ine huremu hwemakirogiramu maviri ine kupisa kwakananga kwe130 J.kg -1 C -1 . Huwandu hwekupisa hunotorwa netin kuti huwedzere tembiricha yayo kubva pa50 o C kusvika 100 o C ndi….
Kukurukurirana
Zvinozivikanwa kuti:
Huremu (m) = 2 kg
Kupisa kwesimbi chaiyo (c) = 130 J.kg -1 C -1
Kuchinja kwetembiricha (Δ T) = 100 o C – 50 o C = 50 o C
Mubvunzo: Kupisa (Q) kunotorwa netini
Mhinduro:
Fomura yekupisa:
Q = mc Δ T
Tsananguro: Q = kupisa, m = uremu, c = kupisa kwakananga, Δ T = kuchinja kwekupisa
Kupisa kunonyudzwa netini:
Q = (2 kg)(130 J.kg -1 C -1 )(50 o C)
Q = (100)(130)
Q = 13000 Joule
Q = 1,3 x 10 4 Joule
2. Mhangura ine kupisa kwakananga kwe390 J kg -1 o C -1 inosangana nekuchinja kwekupisa kwe40 o C. Kana kupisa kwakatorwa nemhangura panguva yekuchinja kwekupisa kuri macalorie mazana maviri, saka huremu hwemhangura...
Kukurukurirana
Zvinozivikanwa kuti:
Kupisa kwakananga kwemhangura (c) = 390 J kg -1 o C -1
Kuchinja kwetembiricha (Δ T) = 40 o C
Kupisa (Q) = 40 Joules
Mubvunzo: Huremu (m) hwemhangura
Mhinduro:
Q = mc Δ T
40 = (m)( 390 )(40 o C)
40 = (m)(390 )(40)
40 = (m)( 390 )(4)
40 = (m)( 1560 )
m = 40 / 1560
m = 0,026 kg
Huremu hwemhangura hunosvika 26 gramu.
3. Mvura ine huremu hwemagiramu makumi maviri ine kupisa kwakananga kwe1 cal g -1 o C -1 pakutanga ine tembiricha ye30 o C. Sarudza shanduko yetembiricha yemvura kana huwandu hwekupisa hunotorwa nemvura huri macalorie mazana matatu!
Kukurukurirana
Zvinozivikanwa kuti:
Huremu (m) = 20 gr
Tembiricha yekutanga (T 1 ) = 30 o C
Kupisa kwemvura chaiyo (c) = 1 cal gr -1 o C -1
Kupisa (Q) = 300 cal
Kubvunzwa: Kuchinja kwekupisa kwemvura
Mhinduro:
Q = mc Δ T
Q = mc (T 2 - T 1 )
300 cal = (20 gr)( 1 cal gr -1 o C -1 )(T 2 – 30 o C)
300 = (20)(1)(T 2 - 30)
300 = 20 (T 2 - 30)
300 = 20 T 2 - 600
300 + 600 = 20 T 2
900 = 20 T 2
T 2 = 900 / 20
T 2 = 45 o C
Kuchinja kwekupisa:
Δ T = 45 o C – 30 o C
ΔT = 15 o C
4. Huwandu hwekupisa hunodiwa kuderedza tembiricha ye4 kg yemvura ine kupisa kwakananga kwe500 J/kg K kubva pa40 oC inova 20 oC iri…
A. 20 kJ
B. 30 kJ
C. 40 kJ
D. 50 kJ
E. 60 kJ
Kukurukurirana:
Zvinozivikanwa :
Huremu (m) = 4 kg
Kupisa kwakananga (c) = 500 J/kg K = 500 J/kg Co
Kuchinja kwetembiricha (delta T) = 40 oC - 20 oC = 20 Co
Akabvunzwa :
Kupisa (Q)
Jawab :
Fomura yekupisa :
Q = (m)(c)(delta T)
Q = (4)(500)(20) = 40.000 Joules = 40 kJ
kJ = kilo Joule
Mhinduro chaiyo ndiC.
5. Chinhu chakasimba chine huremu hwe2 kg chinodziiswa kubva patembiricha ye30oC inova 100oC, inoda kupisa kwe7 × 105 Joule. Kupisa kwechinhu chacho ndekwekuti…
A. 400 J/kg K
B. 500 J/kg K
C. 700 J/kg K
D. 1000 J/kg K
E. 5000 J/kg K
Kukurukurirana:
Zvinozivikanwa :
Huremu (m) = 2 kg
Kupisa (Q) = 7 × 105 J = 700.000 J
Kuchinja kwetembiricha (delta T) = 100 oC - 30 oC = 70 Co
Akabvunzwa :
Kupisa kwakananga (c)?
Jawab :
c = Q / m T
c = 700.000 J / (2 kg)(70 Co) = 700.000 J / 140 kg Co
c = 5000 J/kg Co
c = 5000 J/kg K
Mhinduro chaiyo ndiE.
