Which statement best explains the difference between velocity and speed? a) speed is a vector and requires a direction to completely describe it. b) velocity is a vector and requires a direction to completely describe it. c) speed is measured in units of meter and velocity is measured in units of meters per second. d) velocity is measured in units meters per second and speed is measured in units of miles per hour.

If an astronaut takes an object to the moon the following is true (choose only one). a the mass will change but the weight will be the same. b both the mass and the weight of the object will be the same. c the weight will change but the mass will be the same. d both the mass and the weight of the object will change.

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.

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?