Answer:
at d the charge will be 3q and at 3d it will be 9q
Explanation:
for V=Vp-V2d
V=KQ/d=K*6q/2d=3kq/d for potential to 2d at 6q be zero the Vp will equal 3kq/d; hence at d, Q=3q and at 3d, Q=9q
Answer:
the child is 1.581 m far from the fence
Explanation:
The diagrammatic illustration that give a better view of what the question denote can be seen in the image attached below.
From the image attached below, let assume that the release point is the origin, then equation of the motion (x) is as follows:

---- (1)
the equation of the motion y is :






By using the quadratic formula, we have;

where;
a = 4.9, b = -5.14 c = 1







In as much as the ball is traveling upward, then we consider t= 0.258sec.
From equation (1)




Thus, the child is 1.581 m far from the fence
Answer:
3. you need to ask your available lab instructors what to do.
4. You immediately have to drop down your cloth and roll it to extinguish the fire or move to the emergency shower if available
5. You have too keep calm and report to the lab instructor but do no shout.
6. Move immediately to the eye rinse basin if available and wash your eyes gently and thoroughly