1. explain how scientific knowledge and reasoning can us make difficult decisions. 2. describe a sound wave. discuss what determines pitch and volume. 3. describe the electromagnetic spectrum, electromagnetic waves, and give two examples of different types of electromagnetic waves.

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is