An object travels North at # 4 m/s# for #1 s# and then travels South at # 2 m/s# for # 4 s#. What are the object's average speed and velocity?

1 Answer
May 9, 2017

Answer:

#S_av# of object is #= 2.4 m/s#

#V_av# of object is #=4/5 m/s#

Explanation:

The displacement of the object going #N# for #1s# is:

#N- ((4m)/s)*1s = 4m#

The displacement of the object going #S# for #4s# is:

#S- ((2m)/s)*4s = 8m#

We can take #S# as the positive direction in this case where #N# is opposite, so total displacement is:

#D=8m-4m=4m#

Time taken for the displacement is: #t=5s#

Average velocity is the displacement divided by the total time:

#V_av=(4m)/(5s)=4/5 m/s#

The total distance traveled is #4m+8m=12m

Average speed is the distance traveled divided by the time.

#S_av=(12m)/(5s) = 12/5 m/s = 2.4 m/s#