An object travels North at #9 m/s# for #2 s# and then travels South at #7 m/s# for # 3 s#. What are the object's average speed and velocity?

1 Answer
Apr 4, 2018

Answer:

The average speed is #=7.8ms^-1#. The average velocity is #=0.6ms^-1#

Explanation:

The total distance travelled is

#d=(9*2)+(7*3)=18+21=39m#

The total time is #t=2+3=5s#

The average speed is

#barv=d/t=39/5=7.8ms^-1#

The effective distance travelled is #d_1=18-21=-3m#

The average velocity is #v_1=|d_1|/t=3/5=0.6ms^-1#