Answer:
F = 316.22 N
Explanation:
Given that,
The wind blows a jay bird south with a force of 300 Newtons.
The jay bird flies north, against the wind, with a force of 100 newtons.
Both the forces are acting perpendicular to each other. The net force is given by the resultant of forces as follows :

Hence, the net force on the jay bird is 316.22 N.
Answer:
a.3.20m
b.0.45cm
Explanation:
a. Equation for minima is defined as: 
Given
,
and
:
#Substitute our variable values in the minima equation to obtain
:

#draw a triangle to find the relationship between
and
.
#where 

Hence the screen is 3.20m from the split.
b. To find the closest minima for green(the fourth min will give you the smallest distance)
#Like with a above, the minima equation will be defined as:
, where
given that it's the minima with the smallest distance.

#we then use
to calculate
=4.5cm
Then from the equation subtract
from
:

Hence, the distance
is 0.45cm
Answer:
The elastic potential energy is zero.
The net force acting on the spring is zero.
Explanation:
The equilibrium position of a spring is the position that the spring has when its neither compressed nor stretched - it is also called natural length of the spring.
Let's now analyze the different statements:
The spring constant is zero. --> false. The spring constant is never zero.
The elastic potential energy is at a maximum --> false. The elastic potential energy of a spring is given by

where k is the spring constant and x the displacement. Therefore, the elastic potential energy is maximum when x, the displacement, is maximum.
The elastic potential energy is zero. --> true. As we saw from the equation above, the elastic potential energy is zero when the displacement is zero (at the equilibrium position).
The displacement of the spring is at a maxi
num --> false, for what we said above
The net force acting on the spring is zero. --> true, as the spring is neither compressed nor stretched
Answer:
U = 1 / r²
Explanation:
In this exercise they do not ask for potential energy giving the expression of force, since these two quantities are related
F = - dU / dr
this derivative is a gradient, that is, a directional derivative, so we must have
dU = - F. dr
the esxresion for strength is
F = B / r³
let's replace
∫ dU = - ∫ B / r³ dr
in this case the force and the displacement are parallel, therefore the scalar product is reduced to the algebraic product
let's evaluate the integrals
U - Uo = -B (- / 2r² + 1 / 2r₀²)
To complete the calculation we must fix the energy at a point, in general the most common choice is to make the potential energy zero (Uo = 0) for when the distance is infinite (r = ∞)
U = B / 2r²
we substitute the value of B = 2
U = 1 / r²