-1- was created in the 1600 by william gilbert
-2-When the charge is positive, electrons in the metal of the electroscope are attracted to the charge and move upward out of the leaves. This results in the leaves to have a temporary positive charge and because like charges repel, the leaves separate. When the charge is removed, the electrons return to their original positions and the leaves relax
3-
An electroscope is made up of a metal detector knob on top which is connected to a pair of metal leaves hanging from the bottom of the connecting rod. When no charge is present the metals leaves hang loosely downward. But, when an object with a charge is brought near an electroscope, one of the two things can happen.
Answer:
The total momentum of the universe is always the same and is equal to zero. The total momentum of an isolated system never changes. Momentum can be transferred from one body to another.
Momentum quantifies how likely an object is to stay in motion. Momentum can also be explained using the equation, p=mv, where p is equal to momentum, m is equal to mass, and v is equal to velocity.
Explanation:
3.0 A i got it off Quizlet and there usually always right lol can't submit tho my answers to short.... Dot dot dot
Answer:
The magintude of the acceleration for both objects is 
Explanation:
Drawing a free body diagram on the two boxes we can analyze the system more easily.
we can take the acceleration going up as positive for reference purposes.
for mA let's suppose that is ascending so:

and for mB (descending):


because the two boxes has the same acceleration because they are attached together:

So the magintude of the acceleration for both objects is 
Answer:
E = -4000 N / C
Explanation:
The potential and electric field are related
V = - E s
E = - V / s
we reduce the magnitudes to the SI system
s = 4 mm (1 m / 1000 mm) = 0.004 m
we calculate
E = - 16 /0.004
E = -4000 N / C