Answer:
29.4 uN
Explanation:
The electric force between two charges can be calculated using Coulomb's Law. According to this law the force between two point charges is given as:

where k is a proportionality constant known as the Coulomb's law constant. Its value is
Nm²/C²
r = distance between charges = 70 cm = 0.7 m
q1 = q2 = 4nC =
C
The negative sign indicates that the charges are negative. In the formula we will only use the magnitude of the charges.
Using these values in the formula, we get:

Therefore, the magnitude of repulsive force between the given charges will be 29.4 uN
Speed=distanse/time
144/12=12
ans is 12m/s
from the question
x₁ = x-coordinate = 8
y₁ = y-coordinate = - 4
m = slope of line = 2/3
slope form of the line is given as
(y - y₁ ) = m (x - x₁)
inserting the values
(y - (- 4) ) = (2/3) (x - 8)
(3) (y + 4) = (2) (x - 8)
multiplying each term inside the bracket by 3 and 2 respective on left and right side
3y + 12 = 2 x - 16
2 x - 3 y - 16 - 12 = 0
2 x - 3 y - 28 = 0
Well C is definitely one of the correct answers.