When you are measuring the length of simple pendulum's moment arm (distance to center), which statement is right. (ppt)
a) measure the distance between the center of mass of the pendulum bob and the pivot of the string.
b) the string doesn't need to be taut
c) pivot and center of mass of bob are same thing
they are playing too much beyblade in the office
real, smaller and upside-down. so the answer should be b.