1. The problem statement, all variables and given/known data hey sorry about this again but i'm having trouble with some questions : http://www.physics.ox.ac.uk/Admissions/undergraduate/admissions_test/tests07.pdf [Broken] 3. The attempt at a solution page 6) okay well the bit i'm not sure about here is that L(cm) seeing as it is the distance to the COM i substituted r/2 for the uniform rod and r for the one with the bob giving me; i guess it makes sense because it would go to my simplified versions when simplified then with the 24 hour one it's really tricky... i worked out how much a time period would be to give a difference of 1 day + 1 second, then I worked out what the difference in r would be which gave me; 0.469K for brass and 7.429K for invar, do you think that's reasonable? note i used the formula for a pendulum of negligible mass and a mass on the end. and page 10) question 6, I literally have no idea, i KNOW that it's a silly rule or something reguarding a equilateral triangle in a circle or some rule you can draw on however i'm just blank on this one, any pointers in the right direction would be great... thanks again!