An unknown material, m1 = 0.45 kg, at a temperature of T1 = 91 degrees C is added to a Dewer (an insulated container) which contains m2 = 1.3 kg of water at T2 = 23 degrees C. Water has a specific heat of cw = 4186 J / (kg⋅K). After the system comes to equilibrium the final temperature is T = 31.4 degrees C.

a. Input an expression for the specific heat of the unknown material.

b. What is the specific heat in J (kgK) ?

Question

Reed Skinner

Physics

11 September, 15:31

An unknown material, m1 = 0.45 kg, at a temperature of T1 = 91 degrees C is added to a Dewer (an insulated container) which contains m2 = 1.3 kg of water at T2 = 23 degrees C. Water has a specific heat of cw = 4186 J / (kg⋅K). After the system comes to equilibrium the final temperature is T = 31.4 degrees C.

a. Input an expression for the specific heat of the unknown material.

b. What is the specific heat in J (kgK) ?

+4

Answers (1)

Know the Answer?

Mark West · Answer 1

Let the specific heat of material be s

heat lost by material = m₁ s (T 1 - T), (T 1 - T) is fall in temp, m₁ is mass of material

=.45 x s x (91 - 31.4)

= 26.82 s

Heat gained by water

= m₂ cw (T2 - T)

1.3 x 4186 x (31.4 - 23)

heat lost = heat gained

m₂ cw (T2 - T) = m₁ s (T 1 - T)

1.3 x 4186 x (31.4 - 23) =.45 x s x (91 - 31.4)

45711.12 = 26.82 s

s = 1704.36