CBSE Class 11-science Answered

Let the equation of displacement x as a function of time t  is

.....................................(1)

where A = 5 cm  is amplitude ( magnitude of maximum displacement ) , ω is angular frequency

and is initial phase .

Angular frequency ω = (2π)/T , where T = 2 s is period of oscillation of pendulam .

ω = (2π)/2 rad/s = π rad/s

It is given that at time t = 0 , bob of pendulam is at x = 5 cm , i.e, at extreme right side of equilibrium position .

Hence if we substitute t = 0 , amplitude A = 5 cm and ω = π rad/s in eqn(1) , then we get

5 = 5 cos()   or  = 0

the equation of displacement x as a function of time t  is

x(t) = ( 5 cm ) cos(π t )