In 2012, germans paid 1.65 euros per liter of gasoline. at the same time, american prices were $3.90 per gallon. a. how much would one gallon of european gas have cost in dollars? b. how much would one liter of american gasoline have cost in euros? (one us dollar = 0.76 euros, 1 gallon = 4.55 liters)

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

Often called simply "velocity," this is the velocity of an object at a particular moment in time.

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".