STOICHIOMETRY PLS HELP

What is the difference between electrically neutral objects and electrically charged objects

Figure 9 on page 362 shows various motions of balls. the curved path followed by the yellow ball in b in picture b is result of a) inertia b) centripetal motion c) gravity and horizontal velocity d) linear motion

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k