An object travels North at #15# #m# #s^(-1)# for #2 s# and then travels South at #2# #m# #s^(-1)# for #7 s#. What are the object's average speed and velocity?

1 Answer
Jul 22, 2017

The average speed is #=4.89ms^-1#
The average velocity is #=1.78ms^-1#

Explanation:

The total distance travelled is #d=15*2+2*7=44m#

The total time is #t=2+7=9s#

The average speed is

#barv=d/t=44/9=4.89ms^-1#

The displacement is

#Deltax=15*2-2*7=16m#

The average velocity is

#=(Deltax)/t=16/9=1.78ms^-1#