Which best describes the difference between speed and velocity?
a) velocity is instantaneous.
b) speed is a vector quantity.
c) speed includes rate of change and direction.
d) velocity includes rate of change and direction.

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

While standing outdoors one evening, you are exposed to the following four types of electromagnetic radiation: yellow light from a sodium street lamp, radio waves from an am radio station, radio waves from an fm radio station, and microwaves from an antenna of a communications system. rank these type of waves in terms of increasing photon energy.

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.