Question

An object travels North at `8 m/s` for `2 s` and then travels South at `3 m/s` for `4 s`. What are the object's average speed and velocity?

Answer 1

Average speed = 4.67 m/s
Average velocity = 0.67 m/s N

Explanation:

Speed, a scalar measurement, is how fast an object moves over a surface; velocity, a vector quantity, is how fast and in what direction.

Speed
= `8m/s +8m/s+3m/s+3m/s+3m/s+3m/s=28m/s` over 6s

Average speed = `28/6=4.667 m/s`

Velocity is how far an object is displaced from its starting point over a period of time.

The object moved 8m/s North x 2s = 16 m North, then 3m/s South x 4s = 12 m South, for a total displacement of 4 m North over 6 seconds.

Average velocity `= ((4m) N)/(6s)=0.67 m/s N`