Answer with Explanation:
We are given that
A=3i-3j m
B=i-4 j m
C=-2i+5j m
a.


Compare with the vector r=xi+yj
We get x=2 and y=-2
Magnitude=
units
By using the formula 
Direction:
By using the formula
Direction of D:
b.E=-A-B+C


units
Direction of E=
Answer:
mass =25 kg
using clockwise moment = anticlockwise moment
No, they have different definitions
You'll hear that force called different things in different places. It
may be called "electromotive force", "EMF", "potential difference",
or "voltage".
It's just a matter of somehow causing the two ends of the wire
to have different electrical potential. When that happens, the
free electrons in the copper suddenly have a burning desire to
travel ... away from the end that's more negative, toward the end
that's more positive, and THAT's an "electric current".
To develop the problem it is necessary to apply the equations related to the moment of inertia.
The given values can be defined as,




According to the definition of the moment of inertia applied to the exercise we can arrive at the equation that,

Where n is the number of spokes necessary to construct the wheel.


Replacing the values at the general equation we have,

Solving for n,

Therefore the number of spokes necessary to construct the wheel is 36
PART B) The mass of the wheel is given by the sum of all masses and the total spokes, then



Therefore the mass of the wheel must be of 1.36Kg