More acceleration practice , PLEASE HELP ME 1.A race car starts and finishes a race that is 50,000m. (30miles). The time is 23 minutes. The final velocity is 67m/s. What is the average acceleration?

2.The same car, after crossing the finish line, has a velocity of 45m/s. after 25 seconds. What was the acceleration for this time period?

3.The same car, after the time period in question 2, within 0.5 minute, slows to a constant speed of 20m/s. What was its acceleration for this time period? What is its acceleration after this 0.5 minute time period?

4.The same car, then follows a curve in the road at the same speed. Describe its acceleration. This same car then accelerates at 2m/s2. What will be its velocity after 10 seconds?

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