Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions

.a room with floor measurement 7m by10m air of mass 250kg at a temperature of 34 degree celsius.The air is cooled until the temperature falls to 24 degrees

celsius.(i)calculate the height of the room.(ii)quantity of energy extracted to cool the room.(iii)which is higher,the calculate value or actual energy needed to cool the room?give a reason for your answer.(shc of air=1010j/kg/k density of air 1.25kg/m cube)
but,ur age is given-10
there is a mistake in that, i am 17, i need answer for part 3
i dont know,i cn only calculate height so it's impossbl 4 me :P



This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Room floor area : 7 m * 10 m
mass of air :  250 kg 
Temperature T₀ = 34⁰ C
T₁ = 24° C

Air density 1.25 kg / m³   - let us take that this is the density at 34⁰ C
Volume of the room  = mass of air / density = 250 / 1.25 = 200 m³
Height of the room = volume / floor area = 200 / 70 = 2.855 m
shc of air : specific heat capacity of air = 1010 J/ kg/ °K 
Heat extracted when air is cooled from 34° to 24°C : ΔQ = m s ΔT
           = 250 * 1010 * (34 - 24) = 2,525 KJ
The actual energy needed (to be extracted) to cool the room is more than the calculated value.  One needs to cool the walls also, while cooling the air in the room.  The walls try to heat the room continuously.  The air outside the room also tries to heat the room.  So that additional heat is also to be extracted out.

1 5 1
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts