In a harry potter movie, there is a big pendulum in the great hall that goes back and forth once every 18.9 s. what is the length of the pendulum(if it obeys physics instead of magic)? (unit=m) PLEAS HEL M

Ahorizontal wire is tied to supports at each end and vibrates in its second-overtone standing wave. the tension in the wire is 5.00 n, and the node-to-node distance in the standing wave is 6.28 cm. (a) what is the length of the wire? (b) a point at an anti- node of the standing wave on the wire travels from its maximum upward displacement to its maximum downward displacement in 8.40 ms. what is the wire's mass?

A17,250 kg rocket is pushed with a thrust of 6,450,284 n. what is the acceleration of the rocket?

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.