An object travels North at # 6 m/s# for #6 s# and then travels South at # 3 m/s# for # 7 s#. What are the object's average speed and velocity?

1 Answer
May 1, 2018

Answer:

#Avg. Speed = 57/7 ms^-1#
#Avg. Velocity = 15/13 ms^-1# (northwards)

Explanation:

#Avg Speed = (Total Dist.) / (Total time)#
# = (6xx6 + 3 xx 7)/(6 + 7) = 57/13 m/s#
(Distance = Speed x Time)
Total Displacement is 36 - 21. The object went 36 m north and then 21 m south. Thus it is displaced by 15 m from its origin. #Avg. Velocity = (Total Displacement)/(Total time)#
#= 15/(6+7) = 15/13 m/s#

You may wish to specify that the displacement is in the north direction.