An object travels North at #8 m/s# for #4 s# and then travels South at #5 m/s# for #7 s#. What are the object's average speed and velocity?

1 Answer
Jul 28, 2017

The average speed is #=6.09ms^-1#
The average velocity is #=0.27ms^-1#

Explanation:

The total distance travelled is #d=8*4+5*7=32+35=67m#

The total time is #t=7+4=11s#

The average speed is

#barv=d/t=67/11=6.09ms^-1#

The displacement is

#Deltax=8*4-5*7=32-35=-3m#

The average velocity is

#=(Deltax)/t=3/11=0.27ms^-1#