An object travels North at #2 m/s# for #9 s# and then travels South at #4 m/s# for #5 s#. What are the object's average speed and velocity?

1 Answer
May 7, 2016

Answer:

#"displacement="-2 m#
#"velocity="-1/7 m/s#
#"speed="19/7 m/s#

Explanation:

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#"displacement to the north direction: "v*t=2*9=18m#
#"displacement to the south direction:"v*t=4*5=20m#

#"displacement="-2 m#

#"velocity"=("displacement")/"time"#

#"velocity=(-2)/(9+5)#

#"velocity="-2/14#

#"velocity="-1/7 m/s#

#"speed="("distance")/("time")#

#"speed="(2*9+4*5)/(9+5)#

#"speed="(18+20)/14#

#"speed="38/14#

#"speed="19/7 m/s#