2. A 20.9 kg box of nails is resting on a floor. The coefficient of kinetic friction is 0.457 and the coefficient of static friction is 0.659.
a) What force is required to start it moving?
b) What force is required to accelerate it at 1.19 m/s2?
c) What force is required to move it at a constant speed?
d) What is the acceleration of the box of nails if an elephant kicked it with a force of
538 N?

To understand the electric potential and electric field of a point charge in three dimensions consider a positive point charge q, located at the origin of three-dimensional space. throughout this problem, use k in place of 14? ? 0. part adue to symmetry, the electric field of a point charge at the origin must point from the origin.answer in one word.part bfind e(r), the magnitude of the electric field at distance r from the point charge q.express your answer in terms of r, k, and q. part cfind v(r), the electric potential at distance rfrom the point charge q.express your answer in terms of r, k, and q part dwhich of the following is the correct relationship between the magnitude of a radial electric field and its associated electric potential ? more than one answer may be correct for the particular case of a point charge at the origin, but you should choose the correct general relationship. a)e(r)=dv(r)drb)e(r)=v(r)rc)e(r)=? dv(r)drd)e(r)=? v(r)r