Answer:
1.599 m.
Explanation:
Using
α = ΔL/(LΔT)............ Equation 1
Where
α = Coefficient of linear expansion of brass,
ΔL = Change in length,
ΔT = Change in temperature
L = Original length.
make ΔL the subject of the equation
ΔL = α(LΔT)................. Equation 2
Given: L = 1.6 m, ΔT = T₂-T₁ = 0-28 = -28 ⁰C
Constant: α = 1.8×10⁻⁵/°C
Substitute into equation 2
ΔL = (1.8×10⁻⁵)(1.6)(-28)
ΔL = -8.064×10⁻⁴ m
But,
ΔL = L₁-L
Where L = final length of the pendulum rod.
make L₁ the subject of the equation,
L₁ = ΔL+L......... Equation 2
L₁ = 1.6+( -8.064×10⁻⁴ )
L₁ = 1.599 m.
