Answer:
The speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant is 45 m/s.
Explanation:
Given that, a child threw a stone straight down off a high bridge.
Initial velocity of the stone, u = 15 m/s
We need to find the speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant. When it come down, it is moving under the action of gravity. Using equation of motion as :
So, the speed of the stone before it hit the river 3.00 sec later. Let v is the velocity at that instant is 45 m/s.
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 
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