There are two laws named for Kirchhoff. The both concern electrical circuits.
Here they are in my own words:
1). The sum of the voltage drops around any closed loop in a circuit is zero.
2). The sum of the currents at any single point in a circuit is zero.
Answer:
The inventor of the electric cell was:
Alessandro Volta (in other words, Volta)
Explanation:
I believe the answer is Nonmaterial Culture.
Acceleration (magnitude anyway) = (change in speed) / (time for the change) .
Change in speed = (10 - 30) = -20 m/s
Time for the change = 4.0sec
Magnitude of acceleration = -20/4 = <em>-5 m/s² </em>