Why are sound waves in air characterized as longitudinal?

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.

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.

Adistance-time graph indicates than an object moves 100 m in 4 s and then remains at rest for 6 s. what is the average speed of the object?