Answer:

Explanation:
For this case we have the following info given:
Number of Na+ ions 
Each ion have a charge of +e and the crage of the electron is 
The time is given
if we convert this into seconds we got:

Now we can use the following formula given from the current passing thourhg a meter of nerve axon given by:

Where N represent the number of ions, e the charge of the electron and Q the total charge
If we replace on this case we have this:

And from the general definition of current we know that:

And since we know the total charge Q and the time we can replace:

The current during the inflow charge in the meter axon for this case is 
Boy X and Boy Y both move backward in opposite directions.
Answer:
The distance is
=
7
m
Explanation:
Apply the equation of motion
s
(
t
)
=
u
t
+
1
2
a
t
2
The initial velocity is
u
=
0
m
s
−
1
The acceleration is
a
=
2
m
s
−
2
Therefore, when
t
=
3
s
, we get
s
(
3
)
=
0
+
1
2
⋅
2
⋅
3
2
=
9
m
and when
t
=
4
s
s
(
4
)
=
0
+
1
2
⋅
2
⋅
4
2
=
16
m
Therefore,
The distance travelled in the fourth second is
d
=
s
(
4
)
−
s
(
3
)
=
16
−
9
=
7
m