Which two statements are true of electromagnetic waves? A. They travel by causing particles of matter to vibrate.
B. They do not need a medium to transfer energy.
O C. They transfer energy by disturbing electric and magnetic fields.
D. They need a medium to transfer energy.

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

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.

Robin is swinging back and forth from a trapeze. in which of the following situations is his kinetic energy being transformed into potential energy