What happens to energy and matter when a wave moves through space?

Abird sitting high in a tree is an example of what type of wnergy

The period of a pendulum varies directly as the square root of the length of the pendulum and inversely as the square root of the acceleration due to gravity. find the period when the length is 144 cm and the acceleration due to gravity is 980 cm per second squared, if the period is 7pi seconds when the length is 289 cm and the acceleration due to gravity is 980 cm per second squared.

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?