A clock with an iron pendulum keeps correct time at `20^(@)C`. How much time will it lose or gain in a day if the temperature changes to `40^(@)C`. Thermal coefficient of liner expansion `alpha = 0.000012 per^(@)C`.

Explanation

Given, Coefficient of linear expansion `alpha=12xx10^(-6)//"^(@)C` Change in temperature `Deltatheta=theta_(2)-theta_(1)=40-20=20` Initial time period `T=24xx60xx60=24xx3600=86400` We know that, change in time period,
`Delta T=(1)/(2)TalphaDelta theta=(1)/(2)xx86400xx12xx10^(-6)xx20`
`=12xx10^(-5)xx86400=10368xx10^(-3)`
`10.3` s `days^(-1)`