An object travels North at # 8 m/s# for #9 s# and then travels South at # 5 m/s# for # 2 s#. What are the object's average speed and velocity?

1 Answer
May 11, 2016

Answer:

#v_a=5.64 " "m/s#

#u_a=7.45" "m/s#

Explanation:

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#vec AB=8*9=72 " "m#
#vec CD=5*2=10 " "m#

#"distance="AB+CD=72+10=82 " "m#
#"displacement="vec AB-vec CD=72-10=62 " "m#

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

#v_a=62/(9+2)#

#v_a=62/11#

#v_a=5.64 " "m/s#

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

#u_a=82/11#

#u_a=7.45" "m/s#