Answer:
1.04μT
Explanation:
Due to both wires have opposite currents, the magnitude of the total magnetic field is given by

I: electric current = 10A
mu_o: magnetic permeability of vacuum = 4pi*10^{-7} N/A^2
r1: distance from wire 1 to the point in which B is measured.
r2: distance from wire 2.
The distance between wires is 40cm = 0.4m. Hence, r1=0.2m r2=0.6m
By replacing in the formula you obtain:

hence, the magnitude of the magnetic field is 1.04μT
Answer:
Your friend is 2.143 blocks from the restaurant.
You are 2.857 blocks from the restaurant.
Explanation:
Let t be the time both you and your friend take to walk to the restaurant.
The distance (m) from your building to the restaurant is your walking time t times your speed v1

Similarly the distance (m) from your friend building to the restaurant:

Let b be the length (in m) of a block, the total distance of 5 blocks is 5b





So your friend are 2.143b meters from the restaurant, since each block is b meters long, 2.143b meters would equals to 2.143b/b = 2.143 blocks. And you are 5 - 2.143 = 2.857 blocks from the restaurant.
I believe that the answer is C<span />
The answer is C) rate of change of momentum. The answer is not initial or final momentum as the start and end points are not changing. On the other hand, the time it takes for the ball to change velocity is. This change relates to the change of momentum. Hope this helped :))