can you please answer these questions Q1 Express the boiling

can you please answer these questions?

Q1. Express the boiling point and freezing point of water in F(Fahrenheit), C(Celsius),K (Kelvin), R (Rankine)

Q2. A block of ice, 1/2ft^3 in volume, is taken from a freezer, where it was stored at 32 F(Fahrenheit) (0 C(Celsius)) how many Btu of heat will be required to convert the ice to water at 75 F(Fahrenheit)?

Q3.What conclusions about room humidity can you draw from the following results of measurement with a sling psychrometer?

(a) DB>>WB

(b) DB= WB

(c)DB<WB

Problems 1. Express the boiling point and freezing point of water in OF, OC, OK, Rankine. M2 A block of ice, h ft3 in volume, is taken from a freezer, where it was stored at 32 F (0C). How many Btu of heat will be required to convert he ice to water at 75°F? 3 What conclusions about room humidity can you draw from the following results of measure- ment with a sling psychrometer DB WB (b DB WB (c) DB WB 4. A silver spoon, a marble ashtray and a newspa- PROBLEMS 19 per have been lying on a wooden table in a room for several hours. List the items in order of coolness to the touch of a normally warm hand. Why is this so?

Solution

Q1. Boiling Point:

In Celcius, 100^o C

In  Fahrenheit, F = C × 1.8 + 32, F = 212^o F

In Kelvin, K = C + 273 = 373 K

In Rankine, R = C × 1.8 + 32 + 460 = 672 R

Freezing Point:

In Celcius, 0^o C

In  Fahrenheit, F = C × 1.8 + 32, F = 32^o F

In Kelvin, K = C + 273 = 273 K

In Rankine, R = C × 1.8 + 32 + 460 = 492 R

Q2.

0.5 ft³ of ice = 0.5*57.37 pound ice = 28.685 pound.

It requires 144 Btu to change one pound of ice at 32°F to one pound of water at 32°F (i.e. latent heat of melting)

Total latent heat = 144*28.685 = 4130.64 Btu

Heat required to increase the temperature of water = Weight of material (lbs) x Specific Heat (Btu/lb °F) x Temperature rise (°F) = 28.685* 1 *(75-32) = 1233.45 Btu

Total heat requirement = 4130.64 + 1233.45 = 5364.09 Btu

Q3. If the moisture content of the air is very low, it will give up more heat to the cloth and the wet bulb temperature of air will also be lower. On the other hand, if the moisture content of air is high it will loose less heat to the air and wet bulb temperature will be higher. The more is the moisture content of the air, more is the wet bulb temperature.

(a) DB>>WB : Humidity is ver less

(b) DB= WB: 100% relative humidity

(c) DB<WB: The wet bulb temperature of the air is always less than the dry bulb temperature of air. So this is not possible.

Q4.

Newspaper < Marble ashtray < Silver spoon (in order of coolness)

Because silver has higher heat conductivity, so conduction heat flow will be maximum in spoon. In newspaper it will be lowest as it is having near to insulating behavior.