Two horizontal forces, vector F 1 and vector F 2 , are acting on a box, but only vector F 1 is shown in the drawing. vector F 2 can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the surface.
a) What is the direction of vector F 2 and how does its magnitude compare to the magnitude of vector F 1 when the acceleration of the box is positive?

a. vector F 2 may be positive and have any magnitude. vector F 2 may also be negative, provided that its magnitude is greater than the magnitude of vector F 1.
b. vector F 2 must be negative and may have any magnitude.
c. vector F 2 may be positive or negative and have any magnitude in either case.
d. vector F 2 may be positive and have any magnitude. vector F 2 may also be negative, provided that its magnitude is less than the magnitude of vector F 1.
e. vector F 2 may be negative, but only if its magnitude is greater than the magnitude of vector F 1.


(b) What is the direction of vector F 2 and how does its magnitude compare to the magnitude of vector F 1 when the acceleration of the box is negative?

a. vector F 2 must be positive and may have any magnitude.
b. vector F 2 may be negative, provided that its magnitude is greater than the magnitude of vector F 1. vector F 2 may also be positive and may have any magnitude.
c. vector F 2 must be negative and have a magnitude that is greater than the magnitude of vector F 1.
d. vector F 2 may be positive or negative and may have any magnitude in either case.
e. vector F 2 may be positive or negative, provided that its magnitude is less than the magnitude of vector F 1 in either case.


(c) What is the direction of vector F 2 and how does its magnitude compare to the magnitude of vector F 1 when the acceleration of the box is zero?

a. vector F 2 must be negative and may have any magnitude.
b. F 2 must be positive and have a magnitude that is equal to the magnitude of vector F 1.
c. vector F 2 must be negative and have a magnitude that is less than the magnitude of vector F 1.
d. vector F 2 may be positive or negative, provided that its magnitude is equal to the magnitude of vector F 1.
e. vector F 2 must be negative and have a magnitude that is equal to the magnitude of vector F 1.