The answer is A: can change
Answer:
The value is 
Explanation:
From the question we are told that
The magnitude of the horizontal force is 
The mass of the crate is 
The acceleration of the crate is 
Generally the net force acting on the crate is mathematically represented as

Here
is force of kinetic friction (in N) acting on the crate
So

=> 
I think its Coulomb's law<span>
</span>
Answer:
170N
Explanation:
First add 530N to 150N and you get 680N, then add 400N to 450N and get 850N. So subtract 850N by 680N and you get 170N