Question #6c7ad

1 Answer
Feb 19, 2017

1.74s, rounded to two decimal places

Explanation:

The linear thermal expansion of an object can be expressed as

dl = L_0 α (t_f - t_i)
where dl is change in length, L_0 is initial length, α is Coefficient of linear expansion of the material of the object, t_f and t_i are initial and final temperatures respectively.

Inserting given values and taking alpha=2.22xx10^-5"^@C^-1 we get
dl = 0.75xx2.22xx10^-5 (42 - 25)
=>dl = 0.75xx2.22xx10^-5 (42 - 25)=0.000283m
New length of pendulum's wire=L_0+dl =0.75+0.000283=0.750283m

Time period T of a simple pendulum is given by

T=2pisqrt(l/g)
Where l is length of pendulum and g is acceleration due to gravity and =9.81ms^-2

:. T_"new"=2pisqrt(0.750283/9.81)=1.74s, rounded to two decimal places