Hope you can offer me some help with this question - I feel close to getting it myself but have spent ages looking at it now. Question and working so far is attached. I think what I need to do to enable me to perform the integral is to get theta as a function of time, or instead somehow convert the integral so I am integrating with respect to theta (with limits 0 and pi/2 ). But I am stuck at this point. n.b. Angular velocity omega is written as theta_dot in my notation. Thanks for any help in advance.