Answer:
T₁ = 90°C
Explanation:
Let system 1 => brass sample & system 2 => water
∑q = 0 = q₁ + q₂ = (mcΔT)₁ + (mcΔT)₂
= [(52.9g)(0.375j/g°C)(18.4°C - T₁)]₁ + [(100.0g)(4.184j/g°C)(18.4°C - 15°C)]₂ = 0
=> 19.83(18.4°C - T₁) + 1423 = 0 => 365 - 19.83T₁ + 1423 = 0
=>19.83T₁ = 1788 => T₁ = (1788/19.83)°C = 90°C