An object travels North at #7 m/s# for #9 s# and then travels South at #6 m/s# for # 2 s#. What are the object's average speed and velocity?

1 Answer
Aug 26, 2017

#"Average Speed"= 75/11 m/s#
#"Average Velocity"=51/11 m/s#

Explanation:

Object Travel North
Time taken = 9 s
speed = 7 m/s
Travel Distance = #speed * time=7*9=63 m#

Object Travel South
Time taken = 2 s
speed = 6 m/s
Travel Distance = #speed * time=6*2=12 m#

#"Average Speed"= "total distance "/ "total time" =(63+12)/(9+2)=75/11 m/s#

Displacement
object travel 63 m towards North and 12 m towards south
#total displacement=63-12=51 m#

#"Average Velocity"="Total displacement"/"total time" =(63-12)/(9+2)=51/11 m/s#