An object travels North at #9 m/s# for #5 s# and then travels South at #7 m/s# for # 3 s#. What are the object's average speed and velocity?

1 Answer
Dec 11, 2016

Answer:

Average Speed: #8.25# m/s
Average Velocity: #3# m/s North

Explanation:

#9 m/s N# for #5# s
#rarr # distance traveled: #45 m#; displacement: #45 m N#

#7 m/s S# for #3# s
#rarr # distance traveled: #21 m#; displacement: #21 m S#

Total Distance traveled for #8# s: #45+21 m =66 m#
Average Speed: #66 m# / #8 s=8.25 m"/"s#

Total Displacement after #8 # s: #45 mN-21mS=24mN#
Average Velocity: #24 m N"/"8 s=3m"/"s N#