An object travels North at #8 m/s# for #7 s# and then travels South at #3 m/s# for #4 s#. What are the object's average speed and velocity?

1 Answer
Apr 30, 2016

Answer:

speed#=68/11m/s#,Velocity #=4m/s#

Explanation:

Distance traveled due North in 7s @ #8m/s# is =#8xx7=56m#
Distance traveled due South in 4s @ #3m/s# is =#3xx4=12m#
Total Distance traveled #=56m+12m=68m#
Total time taken = #7+4=11s#
So average speed #=(Total Distance )/( time)=68/11m/s#

Now net displacement due North=#56-12=44m# (North,South being oppositely directed)

Hence Average velocity due North#=(Displacement )/(Time)=44/11m/s=4m/s#