A student begins at rest and then walks north at a speed of v1=0.65m/s. The student then turns south and walks at a speed of v2=0.28m/s. Take north to be the positive direction.  a)What is the student's overall average velocity vavg, in meters per second, for the full trip assuming the student spent equal times at speeds v1 and v2?

A student begins at rest and then walks north at a speed of v1=0.65m/s. The student then turns south and walks at a speed of v2=0.28m/s. Take north to be the positive direction. 

a)What is the student's overall average velocity vavg, in meters per second, for the full trip assuming the student spent equal times at speeds v1 and v2? 

b) If the student travels in the stated directions for 30.0s30.0s at speed v1 and 20.0s at speed v2, what is the net displacement, in meters, during the trip?

c) If it takes the student 1.2s to reach the speed v1, from rest, what is the magnitude, in meters per squared second, of the student’s average acceleration during that time?