A clock with a metallic pendulum gains 5 s each day at a temperature of `15^@C` and loses 10 s each day at a temperature of `30^@C`. Find the coefficient of thermal expansion of the pendulum metal.

Options

A. `(1)/(86400)//^@C`
B. `(1)/(43200)//^@C`
C. `(1)/(14400)//^@C`
D. `(1)/(28800)//^@C`

Answer

A

Explanation

Loss of time due to heating a pendulum is given as
`DeltaT=(1)/(2)alphaDeltathetaT`
`implies12.5=(1)/(2)xxalphaxx(25-0)^@Cxx86400`
`implies alpha=(1)/(86400)//^(@)C `