An arbitrary thermometer has the lower fixed point as 20°C and upper fixed point as 45°C. convert 25° in this thermometer scale to values of the (a) centigrade scale (b) Fahrenheit scale (c) kelvin scale; Also convert 90°F to a value of the (d) Celsius scale (e) Kelvin scale and (f ) Arbitrary scale given above..

ADE.me

4 years ago

t
∘
C=t+273.15 K.

(a) 25
o
C=(25+273.15) K=298.15 K

Robert01

4 years ago

~45°C.....100°C....212°F.........373K

~25°C..... x............y..................z

~20°C..... 0°C........32°F...........273K

(a) (45 – 20)/(25 – 20) = (100 – 0)/(x – 0)

25/5 = 100/x

x= 20°C

(b) (45 – 20)/(25 – 20) = (212 – 32)/(y – 32)

25/5= 180/(y – 32)

1= 36/(y – 32)

y= 64°F

(c) (45 – 20)/(25 – 20) = (373 – 273)/(z – 273)

25/5= 100/(z – 273)

1= 20/(z – 273)

z= 293K

(d)
212°F......100°C

90°F........ a

32°F.........0°C

(212 – 32)/(90 – 32) = (100 – 0)/(a – 0)

180/58= 100/a

a= 32.22°C

(e)
212°F......373K

90°F.........b

32°F.........273K

(212 – 32)/(90 – 32)= (373 – 273)/(b – 273)

180/58= 100/(b – 273)

b – 273= 32.22

b= 305.22K

(f)
45°C.....212°F

c............90°F

20°C......32°F

(45 – 20)/(c – 20)= (212 – 32)/(90 – 32)

25/(c – 20)= 180/58

c – 20= 58 × 25 ÷ 180

c= 8.06 + 20

c= 28.06°C.