Answer:
- 0.0481666 °C^-1
Step-by-step explanation:
Linear expansivity of brass, α
α = (2T - 2T0) / T0.dt
T0 = 30°
dt = change in temperature = 30 - 10 = 20°C
T = 15.55 sec
α = (2*15.55 - 2*30) / 30*20
α = (31.1 - 60) / 600
α = - 28.9 / 600
α = - 0.0481666 °C^-1