Which two types of waves require matter in order to travel? A. Light waves B. Sound waves C. Electromagnetic waves D. Water waves

True or false: the revolution of the earth creates day and night as it rotates around the sun

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

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.