Answer:
-273.16 °C
-459.677 °F
0 °K
0 °R
Explanation:
The lowest temperature is the absolute zero.
Absolute zero is at 0 degrees Kelvin, or 0 degrees Rankine, because these are absolute scales that have their zero precisely at the absolute zero.
Celsius and Fahrenheit degrees are relative scales, these have their zeroes above the absolute zero.
Celsius scale has the same degree separation as the Kelvin scale, but the zero is separated by 273.16 degrees. Therefore the lowest temperature in the Celsius scale is -273.16 °C.
The Fahrenheit degrees have the same degree separation as the Rankine degrees, and the zero is 459.67 degrees. Therefore the lowest temperature in the Fahrenheit scale is -459.67 °F.
Drip irrigation
Drip irrigation is one of the most efficient types of irrigation systems. The efficiency of applied and lost water as well as meeting the crop water need ranges from 80% to 90%
Given:
Temperature of water,
=
=273 +(-6) =267 K
Temperature surrounding refrigerator,
=
=273 + 21 =294 K
Specific heat given for water,
= 4.19 KJ/kg/K
Specific heat given for ice,
= 2.1 KJ/kg/K
Latent heat of fusion,
= 335KJ/kg
Solution:
Coefficient of Performance (COP) for refrigerator is given by:
Max
= 
=
= 9.89
Coefficient of Performance (COP) for heat pump is given by:
Max
= 
= 10.89
Answer:
1200KJ
Explanation:
The heat dissipated in the rotor while coming down from its running speed to zero, is equal to three times its running kinetic energy.
P (rotor-loss) = 3 x K.E
P = 3 x 300 = 900 KJ
After coming to zero, the motor again goes back to running speed of 1175 rpm but in opposite direction. The KE in this case would be;
KE = 300 KJ
Since it is in opposite direction, it will also add up to rotor loss
P ( rotor loss ) = 900 + 300 = 1200 KJ