Car travels from point A to point B at a constant speed of 75 km/hr. They then return to A from B at a constant speed of 65 km/hr. What is the average velocity ?

Teacher said that acceleration is not constant

1 Answer
Jan 29, 2018

I think it is #0km"/"h#.

Explanation:

First of all, I don't think that acceleration has to do anything with this. Anyways, let's get right into the problem.

Average velocity is defined by the equation:

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

Know that, displacement is a vector quantity. Here, the displacement is #0#, because they have traveled from A to B, and then back from B to A, so they have covered the same distance, just in opposite direction, and therefore canceling out the opposite vectors.

Plugging in #"displacement"=0#, we get

#"average velocity"=0/"time"=0#

#:.# Average velocity for the whole trip was #0km"/"h#.