Answer: 321 J
Explanation:
Given
Mass of the box 
Force applied is 
Displacement of the box is 
Velocity acquired by the box is 
acceleration associated with it is 

Work done by force is 

change in kinetic energy is 

According to work-energy theorem, work done by all the forces is equal to the change in the kinetic energy
![\Rightarrow W+W_f=\Delta K\quad [W_f=\text{Work done by friction}]\\\\\Rightarrow 375+W_f=54\\\Rightarrow W_f=-321\ J](https://tex.z-dn.net/?f=%5CRightarrow%20W%2BW_f%3D%5CDelta%20K%5Cquad%20%5BW_f%3D%5Ctext%7BWork%20done%20by%20friction%7D%5D%5C%5C%5C%5C%5CRightarrow%20375%2BW_f%3D54%5C%5C%5CRightarrow%20W_f%3D-321%5C%20J)
Therefore, the magnitude of work done by friction is 
Answer:
GAS, LIQUID, CLOUDS
Explanation:
Water can be in three states: solid, liquid and gas, passing from one to another depending on the pressure and temperature.
In this complementation exercise.
When the water cools down the GAS goes to the LIQUID state, these small drops unite and form the CLOUDS
Answer:
B) they show which way iron shavings would align themselves
Explanation:
Let's analyze each statement:
A) they are not affected by their own source --> this is true for both magnetic and electric fields. In fact, both fields are produced (and so affected) by a source (a magnet or a current in the magnetic field case, and an electric charge in the electric field case)
B) they show which way iron shavings would align themselves --> this is only true for the magnetic field. In fact, the pieces of iron will align according to the magnetic field; however, since they are electrically neutral, they are not affected at all by an electric field.
C) they re stronger near the source and get weaker farther away --> true for both magnetic and electric fields.
D) the closer the fields lines, the stronger the fields --> also true for both magnetic and electric fields.
So, the correct answer is B.
Answer:
ecosystem B
Explanation:
because it goes through more animal's and is correct