Which of the following is a true statement? a. electromagnetic waves are longitudinal waves. b. electromagnetic waves do not always need a medium to travel. c. electromagnetic waves consist of only changing electric fields. d. electromagnetic waves can vary in speed, wavelength and frequency.

Agas expands from an initial volume of 0.040 m^3 and an initial pressure of 210 kpa to a final volume of 0.065 m^3 while its temperature is kept constant. how much work is done by the system?

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?

Decreased sensitivity to an unchanging stimulus is known as