Answer:
a
When 

b
When 
Explanation:
From the question we are told that
The radius is R
The current is I
The distance from the center
Ampere's law is mathematically represented as
![B[2 \pi r] = \mu_o * \frac{I r^2 }{R^2 }](https://tex.z-dn.net/?f=B%5B2%20%5Cpi%20r%5D%20%20%3D%20%20%5Cmu_o%20%20%2A%20%20%5Cfrac%7BI%20r%5E2%20%20%7D%7BR%5E2%20%7D)

When 
=> 
But when 
![B = [\frac{\mu_o * I }{ 2 \pi R^2} ]* r](https://tex.z-dn.net/?f=B%20%3D%20%20%5B%5Cfrac%7B%5Cmu_o%20%2A%20%20I%20%7D%7B%202%20%5Cpi%20R%5E2%7D%20%5D%2A%20r)
Answer:

Explanation:
We apply Newton's second law at the crate :
∑F = m*a (Formula 1)
∑F : algebraic sum of the forces in Newton (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
Data:
m=90kg : crate mass
F= 282 N
μk =0.351 :coefficient of kinetic friction
g = 9.8 m/s² : acceleration due to gravity
Crate weight (W)
W= m*g
W= 90kg*9.8 m/s²
W= 882 N
Friction force : Ff
Ff= μk*N Formula (2)
μk: coefficient of kinetic friction
N : Normal force (N)
Problem development
We apply the formula (1)
∑Fy = m*ay , ay=0
N-W = 0
N = W
N = 882 N
We replace the data in the formula (2)
Ff= μk*N = 0.351* 882 N
Ff= 309.58 N
We apply the formula (1) in x direction:
∑Fx = m*ax , ax=0
282 N - 309.58 N = 90*a
a= (282 N - 309.58 N ) / (90)
a= - 0.306 m/s²
Kinematics of the crate
Because the crate moves with uniformly accelerated movement we apply the following formula :
vf²=v₀²+2*a*d Formula (3)
Where:
d:displacement in meters (m)
v₀: initial speed in m/s
vf: final speed in m/s
a: acceleration in m/s²
Data
v₀ = 0.850 m/s
d = 0.75 m
a= - 0.306 m/s²
We replace the data in the formula (3)
vf²=(0.850)²+(2)( - 0.306 )(0.75 )


Equal to 50
law of reflection: angle of incidence equals angle of reflection
The crate’s acceleration is gravity= 9.81m/s^2
The ball’s acceleration is also gravity=9.81m/s^2
The acceleration that Andrew experience during his ride is 3.6m/s²
The formula for calculating centripetal acceleration is expressed as:
a = v²/r
v is the speed
r is the radius
Given the following expression
v = 6m/s
r = 10m
Substitute the given parameters into the formula
a = 6²/10
a = 36/10
a = 3.6m/s²
Hence the acceleration that Andrew experience during his ride is 3.6m/s²
Learn more here: brainly.com/question/1268866