An object travels North at #7 m/s# for #4 s# and then travels South at #6 m/s# for # 7 s#. What are the object's average speed and velocity?
3 Answers
The average speed is
Explanation:
The total distance travelled is
The total time is
The average speed is
The apparent distance travelled is
The average velocity is
Interpreting the question to be asking for 'displacement'
Explanation:
Let the Northern vector be positive.
So the Southern vector is negative.
Let the resultant be
Thus we have:
The displacement (resultant)
So a better representation is:
The total time for this displacement to be occurring is
Note that in how I set this up a negative value means south from the starting point.
So the average
In decimal form this is
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Average speed:
Average speed
Average speed
Average velocity
Explanation:
- Let unit vector along North be
#hatj# . So, unit vector along South will be#-hatj#