Answer:
Magnetic field = 1.41 T
Explanation:
Magnetic field of solenoid, B = μnI
μ = 4π x 10⁻⁷N/A²
Number of turns per meter, 
Current, i = 18.2 A
B = μnI = 4π x 10⁻⁷ x 6.15 x 10⁴ x 18.2 = 1.41 T
Magnetic field = 1.41 T
Answer:
width of slit(a)≅ 0.1mm
Explanation:
Wave length of laser pointer =λ = 685 nm
Distance between screen and slit = L = 5.5 m
Width of bright band = W=8.0cm=0.08m
width of slit=a
recall the formula;
W=(2λL)/a
a=2λL/W
a=(2 *685*10⁻⁹*5.5m)/0.08m
a=7535*10⁻⁹/0.08
a=94187.5 *10⁻⁹
a=0.0000941875m
a=0.0941875mm
a≅0.1mm
I believe it is velocity. But not to sure
She could choose to wear shoes designed to have more friction on the bottom, so she won’t slip as easily... (or she could get like a walker or something to hold onto if she really wanted to show off her new shoes)
Hope this helps x
