Mamie Phipps Clark is a noted woman psychologist, best known for her research on race, self-esteem, and child development. Her work alongside her husband, Kenneth Clark, was critical in the 1954 Brown vs Board of Education case and she was the first black woman to earn a degree from Columbia University.
It is c which is four minutes per day
Answer:

Explanation:
In order to solve this problem, we mus start by drawing a free body diagram of the given situation (See attached picture).
From the free body diagram we can now do a sum of forces in the x and y direction. Let's start with the y-direction:



so:

now we can go ahead and do a sum of forces in the x-direction:

the sum of forces in x is 0 because it's moving at a constant speed.



so now we solve for theta. We can start by factoring mg so we get:

we can divide both sides into mg so we get:

this tells us that the problem is independent of the mass of the object.

we now divide both sides of the equation into
so we get:


so we now take the inverse function of tan to get:

so now we can find our angle:

so

Answer:
q₃=5.3nC
Explanation:
First, we have to calculate the force exerted by the charges q₁ and q₂. To do this, we use the Coulomb's Law:

Since we know the net force, we can use this to calculate q₃. As q₁ is at the right side of q₃ and q₁ and q₃ have opposite signs, the force F₁₃ points to the right. In a similar way, as q₂ is at the left side of q₃, and q₂ and q₃ have equal signs, the force F₂₃ points to the right. That means that the resultant net force is the sum of these two forces:

In words, the value of q₃ must be 5.3nC.