1 dimensional motion ( pls check my understanding & working)

[benny93xp]

i attach here the  question and  my  attempts .. quite confident with Question x, Question y but  not Question Z  . am not sure if the  concept  still applies.

 

[Country Boy]

  There is information left out of "problem z".  Are we to assume that each leg, A to B and B to C, starts initial speed 0 or does A to B start with initial speed 0 and B to C with the speed with which we arrive at B?

If we start a leg with speed [tex]v_0[/tex] and have constant (or average) acceleration a then in time t we will have gone a distance [tex](a/2)t^2+ v_0t[/tex].  Assuming that we started from A to B at initial speed 0 and it takes 1.5 hours at constant (average) acceleration [tex]11 m/s^2[/tex] then the distance from A to B is (5.5)(5400)+ 0(5400)= 29700 meters or 29.7 kilometers.  The final speed would be 11(5400)= 59400 m/s.  Now, do we start the leg from B to C at that speed or do we stop and start over again?

Edited September 5, 2017 by Country Boy