Answer:
(a) The self inductance, L = 21.95 mH
(b) The energy stored, E = 4.84 J
(c) the time, t = 0.154 s
Explanation:
(a) Self inductance is calculated as;
where;
N is the number of turns = 1000 loops
μ is the permeability of free space = 4π x 10⁻⁷ H/m
l is the length of the inductor, = 45 cm = 0.45 m
A is the area of the inductor (given diameter = 10 cm = 0.1 m)
(b) The energy stored in the inductor when 21 A current ;
(c) time it can be turned off if the induced emf cannot exceed 3.0 V;
If the person if slowing down, then this would mean that this would actually be "negative acceleration". Sense this person first did a mile in 10 minutes, and then the next mile that this person did was actually 15 minutes, then this shows you that they actually went a lot slower. And this is why this would be a great example of "negative acceleration".