Answer:
2. square root 4841 and the answer is 69.5
3. 13.3km
4. 63.6
5. 470000
Step-by-step explanation:
My sister just did the test
The picture is cropped, i can't see the question written. Maybe you should send another picture .
Multiply the first equation by 7 and the second equation by 2, and then add.
Step-by-step explanation:
2f - 5g=-9
-7f + 3g=4
To eliminate any variable , we need to make the coefficients same with different sign and add it
the coefficient of 'f' in first equation is 2
the coefficient of 'f' in second equation is -7
We already have different sign so we make the coefficients same
To make the coefficient same , we multiply the first equation by 7 and second equation by 2
So equation becomes
14f - 35g = -63
-14f + 6g = 8
Now when we add both equations, 'f' gets cancelled
-29g = -55
<span>THE AREA OF THE ROOM IS :A=4*2.4=9.6 m^2
THICKNESS t=0.30 m
DIFFERENCE IN TEMPERATURE dT=18-6=12
q=kAdT/dx=kA*dT/t
q=1.3(9.6)(12)/0.30=4992 W=499.2 J/s
In 1 hour or 3600 sec
P=q*T=(499.2 J/s)(3600 s)=1797120 J=1.8 MJ
1.8MJ OF HEAT FLOWS HTROUGH THE WALL IN ONE HOUR</span>
