When an electron is displaced in a semiconductor, the hole that's left behind is

a. attracted to the negative terminal of the voltage source.
b. incapable of carrying a charge.
c. attracted to the anode of the voltage source.
d. considered an impurity in the crystal.

An airplane flying parallel to the ground undergoes two consecutive displacements. the first is 76 km at 39.8◦ west of north, and the second is 156 km at 59.9◦ east of north. what is the magnitude of the plane’s total displacement? answer in units of km. 020 (part 2 of 2) 10.0

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

An object's buoyant force and weight mean the same thing.a. trueb. false