An object travels North at $4 m/s$ for $5 s$ and then travels South at $9 m/s$ for $2 s$ . What are the object's average speed and velocity?

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Answer 1 · 2018-01-14T16:36:13

Average speed = $5.42 m/s$
Average velocity = $0.28 m/s$

We know that average speed = total distance covered/total time taken.

So,total distance covered in this case in 7 seconds is $(4*5)+(9*2)$ meters or, 38 meters,hence average speed is $38/7$ $m/s$ or, $5. 42 m/s$

Now,avergae velocity = total displacement/total time taken

Here,the object has gone $20$ meters to north and $18$ meters to south,hence displacement = $(20-18) m or 2 m$ (taking towards north to be positive)

Hence average velocity is $2/7 m/s$ or, $0.28 m/s$

Answer 2 · 2018-01-14T16:55:09

velocity= $2/7m/s$
speed= $5.4m/s$

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An object travels North at 4 m/s4 m/s for 5 s5 s and then travels South at 9 m/s9 m/s for 2 s 2 s. What are the object's average speed and velocity?