An object travels North at 6 m/s6ms for 3 s3s and then travels South at 7 m/s7ms for 5 s5s. What are the object's average speed and velocity?

1 Answer
Aug 12, 2017

The average speed is =6.625ms^-1=6.625ms1
The average velocity is =2.125ms^-1=2.125ms1

Explanation:

The total distance travelled is d=(6*3)+(7*5)=18+35=53md=(63)+(75)=18+35=53m

The total time is t=3+5=8st=3+5=8s

The average speed is

barv=d/t=53/8=6.625ms^-1¯v=dt=538=6.625ms1

The displacement is

Deltax=(6*3)-(7*5)=18-35=-17m

The average velocity is

=(Deltax)/t=|-17|/8=2.125ms^-1