Answer:
The polar coordinate of 
is 
.
Explanation:
Given a point in rectangular form, that is 
, its polar form is defined by:
(1)
Where:
- Norm, measured in meters.
- Direction, measured in sexagesimal degrees.
The norm of the point is determined by Pythagorean Theorem:
(2)
And direction is calculated by following trigonometric relation:
(3)
If we know that 
and 
, then the components of coordinates in polar form is:
Since 
and 
, direction is located at 3rd Quadrant. Given that tangent function has a period of 180º, we find direction by using this formula:
The polar coordinate of is .
Answer: A) highly mobile electrons in the valence shell
Explanation: conductivity in metals is a result of the movement of electrically charged particles—the electrons. These free electrons also known as valence electrons are free to move, and as a result they can travel through the lattice that forms the physical structure of a metal. The presence of valence electrons determines a metal's conductivity. However, several other factors can affect the conductivity of a metal such as impurities, temperature, magnetic fields etc.
B - A theory seems to be the closest
For rotational equilibrium of the door we can say that torque due to weight of the door must be counter balanced by the torque of external force
here weight will act at mid point of door so its distance is half of the total distance where force is applied
here we know that
now we will have
so our applied force is 72.5 N
Answer:
I_weight = M L²
this value is much larger and with it it is easier to restore balance.I
Explanation:
When man walks a tightrope, he carries a linear velocity, this velocity is related to the angular velocity by
v = w r
For man to maintain equilibrium needs the total moment to be zero
∑τ = I α
S τ = 0
The forces on the home are the weight of the masses, the weight of the man and the support on the rope, the latter two are zero taque the distance to the center of rotation is zero.
Therefore the moment of the masses and the open is the one that must be zero.
If the man carries only the bar, we could approximate it by two open one on each side of the axis of rotation formed by the free of the rope
I = ⅓ m L² / 4
As the length of half the length of the bar and the mass of the bar is small, this moment is small, therefore at the moment if there is some imbalance it is difficult to recover.
If, in addition to the opening, each of them carries a specific weight, the moment of inertia of this weight is
I_weight = M L²
this value is much larger and with it it is easier to restore balance.
