Answer:
20 m/s
Explanation:
The speed of the book can be found by using the formula
[tex]s = \frac{d}{t} \\ [/tex]
d is the distance
t is the time taken
From the question we have
[tex]s = \frac{140}{7} \\ [/tex]
We have the final answer as
20 m/s
Hope this helps you
