What is one way to increase the amplitude of a wave in a medium?
A. by applying a vibration at the natural frequency of the medium
B. by increasing the velocity of the wave source
C. by moving the source of the wave away from the receptor, or observer
D. by decreasing the frequency of the wave source

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

What changes occur in the brain during the teenage years? 25 points, someone me out!a.) thinking becomes slower as the brain grows larger. b.) connections between neurons become stronger and faster. c.) unused neurons fuse together to form larger, better functioning neurons. d.) more neurons are developed.

Amira pulls a 3 pound wagon 4 feet. how much work has she done?