An object travels North at #8 m/s# for #3 s# and then travels South at #6 m/s# for # 7 s#. What are the object's average speed and velocity?

1 Answer
Jan 6, 2017

Answer:

average speed: 6.6 m/s
average velocity: 1.8 m/s South

Explanation:

Object travels North at #8m/s# for #3s#
#rarr# object travels #8m/sxx3s=24 m " North"#
then
it travels South at #6 m/s# for #7 s#
#rarr# object travels #6m/sxx7 s=42 m " South"#

Total distance traveled: #24 m +42 m =66 m#

Total displacement from point of origin:
#color(white)("XXX")24 m N +42 m S=-24m S +42 m S=18 m S#

Total time involved in travel: #3 s+7s=10s#

#"Average speed" = ("total distance")/("total time") =(66 m)/(10 s)=6.6m/s#

#"Average velocity"=("total displacement")/("total time")=(18 m S)/(10 s) =1.8 m/s S#