A student reads the length of an object from a ruler as 7.2 cm, and his teacher says that he is missing an estimated place value, and should have a measurement like "7.20 cm". What is the length (in cm) of the smallest increment on this ruler? Meaning "what is the distance between the tick marks".

The ozone molecule o3 has a permanent dipole moment of 1.8×10−30 cm. although the molecule is very slightly bent-which is why it has a dipole moment-it can be modeled as a uniform rod of length 2.5×10−10 m with the dipole moment perpendicular to the axis of the rod. suppose an ozone molecule is in a 8000 n/c uniform electric field. in equilibrium, the dipole moment is aligned with the electric field. but if the molecule is rotated by a small angle and released, it will oscillate back and forth in simple harmonic motion.what is the frequency f of oscillation?