You notice a light from the ocean approaching you at a speed of 43 m/s. The light has a frequency of 12 Hz. Find the observed frequency.

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Apebble is thrown into a calm lake, ripples are formed from the center and move outward. the water particles in the lake travel in a circular pattern that moves up and down on the surface of a lake, and the energy travels a) diagonally. b) downward. c) horizontally. d) upward.

Which of these is not a possible type of energy transformation? a. electrical energy into light energy b. sound energy into nuclear energy c. potential energy into kinetic energy d. kinetic energy into mechanical energy