Two force always involved in using a machine are

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

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