. A 0.0255 kg silver ring (Cp= 234 J kg-1 ºC-1 ) is heated to 84 ºC and then placed in a calorimeter containing 0.05 kg of water at 24 ºC. The calorimeter is not perfectly insulated, so 0.14 kJ of energy is transferred to the surroundings before a final temperature is reached. What is the final temperature?

T = 37.27°C

Explanation:

We are given;

Mass of silver ring; m_s = 0.0255 kg

Specific heat capacity;Cp= 234 J kg-1 ºC-1

Silver is heated up to a temperature of;T_s1 = 84°

Mass of water;m_w = 0.05 kg

Temperature of water;T_w1 = 24°

Heat transferred to surrounding = 0.14 KJ

Specific heat capacity of water = 4200 J/kg°C

Applying the law of conservation of energy, we have;

Heat from silver cup = Heat gained by calorimeter + heat transferred to the surroundings

Let final temperature be "T"

Formula for heat is Q = m•cp•Δt

Thus;

(0.0255)(234)(84 - T) = [(0.05)(4200)(T - 24)] + 0.14

Expanding, we have;

5.967(84 - T) = 21(T - 24) + 0.14

501.228 - 5.967T = 21T - 504 + 0.14

501.228 + 504 - 0.14 = 21T + 5.967T

1005.088 = 26.967T

T = 1005.088/26.967

T = 37.27°C

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: