An object travels North at $5 m/s$ for $6 s$ and then travels South at $8 m/s$ for $4 s$ . What are the object's average speed and velocity?

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Answer 1 · 2018-06-30T01:18:49

Refer to the explanation.

The total distance traveled was:

$5 \ "m/s"*6 \ "s"+8 \ "m/s"*4 \ "s"$

$=30 \ "m"+32 \ "m"$

$=62 \ "m"$

So, the average speed is:

$bars=d/t$

$=(62 \ "m")/(10 \ "s")$

$=6.2 \ "m/s"$

I'll take North to be the original direction for velocity. So, the total displacement is:

$5 \ "m/s"*6 \ "s"-8 \ "m/s"*4 \ "s"$

$=30 \ "m"-32 \ "m"$

$=-2 \ "m"$

So, the displacement is $2 \ "m"$ south.

The average velocity is therefore:

$barv=(vecd)/t$

$=(-2 \ "m")/(10 \ "s")$

$=-0.2 \ "m/s"$

This means that the average velocity is $0.2 \ "m/s"$ south.

An object travels North at 5 m/s5 m/s for 6 s6 s and then travels South at 8 m/s8 m/s for 4 s4 s. What are the object's average speed and velocity?