Answer:

Explanation:
As we know that moment of force is given as

now we have


now from above formula we have

here we know that

so we have


This is easily explained saying that the frictional force between the books and the paper isn't big enough to produce a displacement in the books. The displacement in the books doesn't happen because the frictional force between the books and the surface they are standing on is bigger than the paper's one.
<span>
</span><span>Waves on a pond are an example of which kind of wave?
</span>B. surface waves
Answer:
the boat would be deeped by 3200 m
Explanation:
Given that
The boat arrives back after 4 seconds
And, the speed of the sound in water is 1,600 m/s
We need to find out how much deep is the water
So,
As we know that
Distance = ( speed × time) ÷ 2
Here we divided by 2 because the boat arrives back
= (1600 × 4) ÷ 2
= 3200 m
Therefore the boat would be deeped by 3200 m