d = distance between the two point charges = 60 cm = 0.60 m
r = distance of the location of point "a" where the electric field is zero from charge 
between the two charges.
= magnitude of charge on one charge
= magnitude of charge on other charge
= 3
= Electric field by charge at point "a"
= Electric field by charge at point "a"
Electric field by charge at point "a" is given as
= k /r²
Electric field by charge at point "a" is given as
= k /(d-r)²
For the electric field to be zero at point "a"
=
k /(d-r)² = k /r²
/(d-r)² = 3 /r²
1/(0.60 - r)² = 3 /r²
r = 0.38 m
r = 38 cm
It’s D. An enlargement (hope this helps!)
Answer:
In a controlled experiment, an independent variable (the cause) is systematically manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. The researcher can operationalize (i.e. define) the variables being studied so they can be objectivity measured.
Answer:
B) The tree was stationary and began to move.
Explanation:
This situation can be explained by using Newton's first law of motion, which states that
"An object at rest (or in motion at constant velocity) stays at rest (or in motion at constant velocity) unless a net non-zero force is exerted on it"
This means that an object at rest can start moving if and only if there is a net non-zero force acting on it.
In the example in the problem, the tree is initially stationary. Later, it started to move. According to Newton's first law, therefore, there must be a net force that caused this change of state of motion of the tree. Therefore, the correct answer is
B) The tree was stationary and began to move.
The inaccurate measurements must be similar to the other two measurements (ex; 590, 589, 599), but different from the actual volume of water. (Ex; the actual volume is let say.. 100, but you measured 50, 49, 40)
