How to do 4th question?

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1 Answer
Mar 15, 2018

See below.

Explanation:

Period is given by

T approx 2pi sqrt(L/g)T2πLg

now taking natural log to both sides

lnT = ln(2pi)+1/2 (ln L - ln g)lnT=ln(2π)+12(lnLlng)

assuming gg constant and deriving

(deltaT)/T = 1/2 (deltaL)/LδTT=12δLL

now assuming an isotropic material the volumetric thermal expansion coefficient is three times the linear coefficient: or

alpha_V = 3 alpha_LαV=3αL and then

delta L = alpha_L (40^@-20^@) = 1/3 alpha_V(40^@-20^@) =1/2(36/3) xx 20 xx10^-6δL=αL(4020)=13αV(4020)=12(363)×20×106 [s]

and finally

(delta T)/T approx 120 xx 10^-6δTT120×106 [s/s]

per day it gives

delta T = 24 xx 60 xx 60 xx 120 xx 10^-6 = 10.38δT=24×60×60×120×106=10.38 [s] delay/day.