The Only Force Acting on a 1

Multiple Choice

The only force acting on a 1.8-kg body as it moves along the x axis is given by F_x = −(3.0x) N, where x is in m. If the velocity of the body at x = 0 is v_x = +8.0 m/s, at what value of x will the body have a velocity of +4.0 m/s?

A) 5.7 m
B) 5.4 m
C) 4.8 m
D) 4.1 m
E) 6.6 m