Answer:
You can determine which charge has the solid by rubbing plastic and fur, and bringing near the plastic and the solid to determine if they are repeled or attracted. If they are repeled, the solid is charged negatively and if they are attracted, the solid is charged positively.
Explanation:
In order to determine the charge of the solid (negative or positive) using a piece of plastic and fur, you have to rubb the plastic with the fur (this is charging by friction)
Negative charges are transferred from the fur to the piece of plastic, therefore the plastic is charged negatively.
Then, you have to bring near the solid and the plastic. If them are repeled, it means that the solid is charged negatively (Because similar charges are repeled)
If them are attracted, it means that the solid is charged positively (Because opposite charges are attracted)
Answer:
(a) 1, average velocity = -65.6 m/s
2, average velocity = -64.8 m/s
3, average velocity = -64.16 m/s
(b) The instantaneous velocity is -96 m/s
Explanation:
(a)
Average velocity is given by;

(1)

(2)

(3)

b. y = 235 - 16t²
The instantaneous velocity is given by;
v = dy /dt
dy / dt = -32t
when t = 3 s
v = -32(3)
v = -96 m/s
As we know that speed of sounds is given as

here we know that
t = 23 degree C
now from above equation we will have


now we also know that distance between two consecutive resonance length is half of the wavelength



now we know that


so frequency will be 786 Hz
Math is the process of using the given information, along with
all the general stuff that you know, to find the missing information.
With no given information, we have no way to even guess at
an answer.
The answer would be intoduction hope this really helped