A pendulum clock (fitted with a small heavy bob
that is connected with a metal rod) is 5 seconds
fast each day at a temperature of 150C and
10 seconds slow at a temperature of 30C. The
temperature at which it is designed to give correct
time is

Answers (1)
S safeer


let t is the temperature at which clock show right timing


the change in period of a pendulum when the temperature is changed by  is

\Delta T=\frac{1}{2}\alpha \theta T_0

5=\frac{1}{2}\alpha (t-15) T_0

5=\frac{1}{2}\alpha (t-15) T_0

at 30 degree loss is 10

-10=\frac{1}{2}\alpha (t-30) T_0

solving t=20C