A neutral object contains no net charge, but still has many charged particles within the object, it just means that the charges cancel each other out.
Answer:

Explanation:
The speed of the waves in a string is related with the tension and mass per unit length of the string, as follows:

First, we calculate the mass per unit length:

Now, we calculate the speed of the waves:

Answer:
a) 1.6*10^6 V
b) 13.35*10^6 V
Explanation:
The electric potential at origin is the sum of the contribution of the two charges. You use the following formula:
(1)
q1 = 3.90µC = 3.90*10^-6 C
q2 = -2.4µC = -2.4*10^-6 C
r1 = 1.25 cm = 0.0125 m
r2 = -1.80 cm = -0.018 m
k: Coulomb's constant = 8.98*10^9 Nm^2/C^2
You replace all the parameters in the equation (1):
![V=k[\frac{q_1}{r_1}+\frac{q_2}{r_2}]\\\\V=(8.98*10^9Nm^2/C^2)[\frac{3.90*10^{-6}C}{0.0125m}+\frac{-2.4*10^{-6}C}{0.018m}]=1.6*10^6V](https://tex.z-dn.net/?f=V%3Dk%5B%5Cfrac%7Bq_1%7D%7Br_1%7D%2B%5Cfrac%7Bq_2%7D%7Br_2%7D%5D%5C%5C%5C%5CV%3D%288.98%2A10%5E9Nm%5E2%2FC%5E2%29%5B%5Cfrac%7B3.90%2A10%5E%7B-6%7DC%7D%7B0.0125m%7D%2B%5Cfrac%7B-2.4%2A10%5E%7B-6%7DC%7D%7B0.018m%7D%5D%3D1.6%2A10%5E6V)
hence, the total electric potential is approximately 1.6*10^6 V
b) For the coordinate (1.50 cm , 0) = (0.015 m, 0) you have:
r1 = 0.0150m - 0.0125m = 0.0025m
r2= 0.015m + 0.018m = 0.033m
Then, you replace in the equation (1):
![V=(8.98*10^9Nm^2/C^2)[\frac{3.90*10^{-6}C}{0.0025m}+\frac{-2.4*10^{-6}C}{0.033m}]=13.35*10^6V](https://tex.z-dn.net/?f=V%3D%288.98%2A10%5E9Nm%5E2%2FC%5E2%29%5B%5Cfrac%7B3.90%2A10%5E%7B-6%7DC%7D%7B0.0025m%7D%2B%5Cfrac%7B-2.4%2A10%5E%7B-6%7DC%7D%7B0.033m%7D%5D%3D13.35%2A10%5E6V)
hence, for y = 1.50cm you obtain V = 13.35*10^6 V
Answer:
A) having each person listen to just 1 song instead of 5.
Explanation:
Ravi could accurately use the outcome to compare the hearing capacities of his friends by this experiment if appropriate precautions are observed.
Playing 5 well known songs simultaneously could result to the interference of sounds when each participant moves away from the player. Which could naturally cause the variation in volume of the songs played with respect to the increasing distance.
Therefore, the reliability of the result from this experiment can be increased if each person listen to just 1 song instead of 5 at a predetermined volume. Each participant would be able to focus on hearing a song during the experiment.
Using the law of conservation of momentum:
m₁u₁ + m₂u₂ = m₁v₁ + m₂ v₂; u₂ = 0
5 x 2 = 5v₁ + 7v₂
10 = 5v₁ + 7v₂
v₂ = (10 - 5v₁)/7
Elastic collision so kinetic energy conserved:
1/2 x 5 x 2² = 1/2 (5v₁² + 7v₂²)
20 = 5v₁² + 7((10 - 5v₁)/7)²
140 = 35v₁² + 5v₁² + 100 - 20v₁
40v₁² - 20v₁ - 40 = 0
v₁ = 1.28 m/s OR v₁ = -0.78 m/s
The first ball is lighter so its velocity will change direction due to collision.
v₁ = -0.78 m/s
10 = 5(-0.78) + 7v₂
v₂ = 1.98 m/s