Question

1. One beaker contains 156 g of water at 22°C, and a second beaker contains 85.2 g
of water at 95°C. The water in the two beakers is mixed. What is the final water
temperature? (2.5 points)

Answer 1

Answer:

47.8°C

Explanation:

By conservation of energy, we know that:

Energy lost by water from 2nd beaker = Energy gained by water in 1st beaker

Since we are talking about thermal energy, we can expand this further to:

mcT = mcT (Bolded is for 2nd beaker and italicised is for 1st beaker)

(85.2)(4.2)(95 - T) = (156)(4.2)(T - 22)   {T denotes the final temperature}

33994.8 - 357.84T = 655.2T - 14414.4

1013.04T = 48409.2

            T = 47.8 °C

[Note: Thermal Energy can be calculated using mcT where m is the mass, c is the specific heat capacity and T is the change in temperature]

                     

Answer 2

Answer:

47.8°C

Explanation: