Answer:
The force on the book is 250N.
Step-by-step explanation:
Newton's second law states that the equation for the force is:

In which m is the mass, in kilograms, and a is the acceleration, in m/s². F is the force measured in N.
In this question:

So

The force on the book is 250N.
Answer:8.7
Step-by-step explanation:
There are 5 shelves in the bookcase.
2/5 of one shelve is occupied.
That would be:
2/5*1/5=2/25 of all shelves
7/2 is more than 1, so it refers to the bookcase instead
of one shelve. The same with 11/10.
So the total is:
2/5+7/2+11/10 = 5
So all shelves are completely full.
So there is no room for any other book.
We can consider each unique

as the as the

-th unit vector. So your set

can be considered as the vectors

Then check for independence your favorite way. In this case, I'll see if the linear map A of the new basis vectors doesn't map to a subspace via the determinant not being zero:
![det(A) = det \left ( \left [ \begin{array}{ccc} 1 & 0 & 0 \\ 0 & 1 & 3 \\ 0 & 1 & 4 \end{array}\right ] \right ) = 1(4-3) = 1](https://tex.z-dn.net/?f=%20det%28A%29%20%3D%20det%20%5Cleft%20%28%20%5Cleft%20%5B%20%5Cbegin%7Barray%7D%7Bccc%7D%201%20%26%200%20%26%200%20%5C%5C%200%20%26%201%20%26%203%20%5C%5C%200%20%26%201%20%26%204%20%5Cend%7Barray%7D%5Cright%20%5D%20%5Cright%20%29%20%3D%201%284-3%29%20%3D%201)
So they are linear independent.
We be back in school I don’t want