An object travels North at #4 m/s# for #3 s# and then travels South at #1 m/s# for # 6 s#. What are the object's average speed and velocity?

1 Answer
Jan 2, 2018

The average speed is #=2ms^-1#. The average velocity is

#=2/3ms^-1#

Explanation:

The total distance travelled is

#d=(4*3+1*6)=12+6=18m#

The time taken for the whole journey is

#t=3+6=9s#

The average speed is

#barv="total distance travelled "/"total time taken"=18/9=2ms^-1#

The effective distance travelled is

#d_(eff)=4*3-1*6=12-6=6m#

The time taken is

#t=9s#

The average velocity is

#="effective distance travelled"/"time taken"=6/9=2/3ms^-1#