If the length of pendulum is 0.8+/-0.01m and time peroid is 2.5+/-0.012 sec. Then percentage error in acceleration due to gravity will be

2 answers

T=2PI(sqrt(l/g)

t^2=(2PI)^2 l/g

g= (2PI)^2*length/time^2

Now error in g is
9.8* (2PI)^2 * g*sqrt {[.01/.8]^2 + [.012/2.5]^2 )

http://lectureonline.cl.msu.edu/~mmp/labs/error/e2.htm
good