An object travels North at 6 m/s for 2 s and then travels South at 6 m/s for 7 s. What are the object's average speed and velocity?

1 Answer
May 25, 2018

Refer to the explanation.

Explanation:

Average speed is defined through the equation:

bars=d/t

where:

  • bars is the average speed

  • d is the total distance covered

  • t is the time taken

So, we get:

bars=(6 \ "m/s"*2 \ "s"+6 \ "m/s"+7 \ "s")/(9 \ "s")

=(54 \ "m")/(9 \ "s")

=6 \ "m/s"

Velocity is given by the equation:

barv=(vecd)/t

where:

  • barv is the average velocity

  • vecd is the distance covered in a specific direction

  • t is the time taken

Here, I'll let the standard direction to be north. So, the south direction will be represented as negative.

So, we get:

barv=(6 \ "m/s"*2 \ "m/s"-6 \ "m/s"*7 \ "s")/(9 \ "s")

=(-30 \ "m")/(9 \ "s")

=-3.bar(3) \ "m/s"

Therefore, the average velocity is 3.33 \ "m/s" south.