As y varies directly with x, there is a proportionality constant. As x increases by that certain constant, y also increases. We equate:
y = kx
where k = proportionality constant.
Given the condition, y = 5 when x = 4, then we solve for k:
5 = k(4)
k = 5/4 or 1.25
When y = 8, then
8 = (5/4)(x)
x = 8/(5/4) = (8)(4/5) = 32/5 or 6.4 (ANSWER)
There is no answer to this question.
The formula is E= kQ/ d^2
k is 9x10^9
i changed 15 cm to 0.15 m
=> 9x10^9 x 12 OVER (0.15)^2
the answer is 4.8x10^12 N/C
but this is the electric field.
to find electric field STRENGTH, it’s E= F/q and you did not give a value for the force
