I need help with the experiment particularly numbers 11 1314

I need help with the experiment, particularly numbers 11, 13,14, 16, 17, and 20. I feel like there may be some human error on my part because just about every observation that I did, the two pith balls attracted to one another. Can someone please help me? I have included each step for the procedure below.

Procedure

1. Tear one small piece of masking tape from the roll (approximately 5 cm).

2. Create a small, closed loop with the tape, leaving the sticky side on the outside of the loop.

3. Secure the looped tape to one of a side of the wooden block adjacent to the side with the slit.

4. Press the taped side of the wooden block onto a smooth wall (or the flat side of a counter or table top) with the slit pointing perpendicular to the wall and parallel to the floor.

5. Unwrap the outer layer of a paperclip.

6. Use the exposed end of the paperclip to poke a hole through the centers of two pith balls.

7. Thread one end of the monofilament line through one of the pith balls. Tie a knot on the end that you threaded through to keep the pith ball on the thread.
Note: If the paperclip created a larger hole, three to five knots may need to be tied to secure the ball on the thread.

8. Repeat Step 7 on the other end of the monofilament line with the other pith ball.

9. Once the pith balls are secured on each end of the line, place the line in the slit of the wooden block. The pith balls should rest at the same height.

10. Remove any charge from the acetate strip (wide and clear) by grabbing it with your hand or rubbing it on a metal object like a door knob. This is called grounding.

11. Test for interactions between the acetate strip and both pith balls. Record observations of any interaction.

12. Charge the acetate strip by rubbing it with the cotton cloth.

13. Slowly bring the plastic strip close enough to the right pith ball so that it moves, but does not touch the plastic strip. Once movement of the pith ball is observed move the plastic strip away. Record your observations (e.g., how far away were the two objects, how fast did the pith ball move, in what direction did the pith ball move, etc.).

14. Slowly bring the plastic strip close enough to the left pith ball so that it moves, but does not touch the plastic strip. Once movement of the pith ball is observed move the plastic strip away. Record your observations.

15. Hold the monofilament line above the right pith ball and bring the ball into contact with the plastic strip.

16. Let the pith ball hang again and bring the plastic rod close to, but without touching the right pith ball. What kind of interaction is observed?

17. Hold the line above the right pith ball and bring it close to the left pith ball. Observe what happens. Let the balls come into contact. How does that change the interaction?

18. Grab the pith balls to ground them and take away any charge they may have.

19. Charge the plastic rod again with the cotton.

20. Hold the line above the right pith ball with your pointer and middle finger. Bring the right pith ball close to the plastic rod, but do not let them touch. This time touch the left side of the ball (the one opposite of the rod) with your thumb. Let the ball hang again. Bring the right pith ball close to the left pith ball. Observe what happens.

Solution

Solution:-

Its an pure electrostatic experiment so the basic rule to be kept in mind is that the “LIKE CHARGES REPEL EACH OTHER, WHEREAS THE UNLIKE CHARGES ATTRACT EACH OTHER”

eg:- if 2 bodies carries +ve charge they will repel each other, whereas if 2 bodies carries 1) +ve and other -ve charge they will tend to move towards each other.

Now be carefully follow each and every step written in the procedure and keep the thumb rule in mind. Kindly follow step 9 and 10 very carefully given in the procedure.

10) Removing charge from acetate strip is very important and dont perform such an experiment in room where humiditity is very high because such conditions will not be suitable to perform experiment.

11) After interacting the acetate strip and both pith balls you will observe an repulsion between the two balls as the acetate strip will give same charge to both the balls and from our basic rule we know kind charges repel each other so, we will observe an repulsion.

13)When we bring the plastic rod near to the pith ball (without touching it), we observe that the ball comes towards the plastic rod and similar will be the case for the other pith ball also given in step nomber (14)

16) Again before this step follow the step 15 very carefully. When we interact the right pith ball and the plastic strip we are basically transfering the charge from one body to the other i.e. from the plastic strip to the pith balls. If now, we bring plastic rod again near to the right pith ball we will oberve that ball will repel the plastic strip.

17) here in step 15 we have only transffered charge of plastic strip to right pith ball. If we see the interaction between the two balls we will notice that the two balls now attract each other. Due to same thumb law given above.

20) not much will happen as one of the ball is being grounded by the thumb.