The answer completely depends on the number that belongs in the space before the word "microfarad".
For the part a) we need only the momentum of the box and we have the data to find it.
Momentum is given by,

where clearly, p is the momentum, m the mass of the box and v is the velocity.
Substituting,

For part b) we need an analysis of the situation. We understand that the box on a surface that has no friction will continue to rotate at the same speed previously defined. The box can only stop with friction, so,

<em>It is the same that part a)</em>
The right answer is b) copper
I’m sorry I wish I knew the answer but I don’t I need this for points I’m so sorry
Answer:
See the answer below
Explanation:
Newton's third law states that for every action, there will always be an opposing reaction of equal magnitude to the action.
<em>Hence, the wall will exert an equal opposing force to the head and the roommate will feel this opposing force as pains and/or headache. </em>