Answer:
a. ρ
b. 
Explanation:
a. To find the density of magnetic field given use the gauss law and the equation:
,
,
Ω,
,
, 
ρ
ρ
ρ
ρ
b. The electric field can be find using the equation:




86.3 I just did the math and that’s the answer I got
Answer:
μ = 0.33
Equal to 3.2 m/s²
Explanation:
Draw a free body diagram of the block. There are three forces:
Normal force N pushing up.
Weight force mg pulling down.
Friction force Nμ pushing opposite the direction of motion.
Sum of forces in the y direction.
∑F = ma
N − mg = 0
N = mg
Sum of forces in the x direction.
∑F = ma
Nμ = ma
Substitute.
mgμ = ma
μ = a/g
μ = (3.2 m/s²) / (9.8 m/s²)
μ = 0.33
As found earlier, the acceleration is a = gμ. Since g and μ are constant, a is also constant, so it does not change with velocity.