Velocity is speed plus the direction of the speed.
-- Light travels straight, not around in a circle. But if it did, it would cover
a distance equal to the length of the equator in about <em>0.13 second</em>.
-- At the speed of sound (in air at standard temperature and pressure),
it would take about <em>32.6 hours </em>to cover the same distance.
Answer:
Explanation:
radius of the solenoid, r = 0.05 m
length of the solenoid, l = 0.39 m
Magnetic field of the solenoid, B = 2 x 10^-5 T
Number of turns, N = 200
The magnetic field of the solenoid is given by

where, i be the current and n be the number of turns per unit length
n = N / l = 200 / 0.39 = 512.8

i = 0.031 A
Answer:
3.7 A
Explanation:
Parameters given:
Magnetic field strength, B = 5 * 10^(-5) T
Distance of magnetic field from wire, r = 1.5 cm = 0.015 m
The magnetic field, B, due to a current, I, flowing a wire is given as:
B = (μ₀*I) / 2πr
Where μ₀ = permeability of free space
To get the current, I, we make I the subject of the formula:
I = (2πr * B) / μ₀
I = (2 * 3.142 * 5 * 10^(-5)) / (1.25663706 × 10^(-6))
I = 3.7 A