Velocity is defined as Distance divided by Time.
In other words, V = D/T.
Now that we have our formula, we can solve.
Let's plug in the numbers we have.
We have 12m [East (direction not necessary when solving yet)] for our distance, and 0.15s as our time.
Divide the distance (12 /) by the time (0.15)
12 / 0.15 = 80.
Your velocity is 80 m/s [E]
I hope this helps!
Answer:
(a) 
(b) neither increasing or decreasing
(c) opposite to the flow of charge carriers
Explanation:
The current through an inductor of inductance L is given by:
(1)
(a) The induced emf is given by the following formula
(2)
You derivative the expression (1) in the expression (2):

(b) At t=0 the current is zero
(c) At t = 0 the emf is:

w, L and Imax have positive values, then the emf is negative. Hence, the induced emf is opposite to the flow of the charge carriers.
(d) read the text carefully