# 7 the answer is 4) because you need opposites in order to attract
# 8 I'm going to guess it is 4) because electricity is needed in order a light bolt to work.(don't take my word for this one I'm not sure but, the other answer are correct)
# 9 the answer is 4) because the comb dose collect negative charges from the hair in order to make the hair have positive charge.
Hope this helped : )
first object gors highest
second object goes lowest.
The goods and the services make up the basis of every economy. The goods can simply be defined as merchandise or possessions. The services can be defined as the actions through which help is provided, or work is done for someone else. Example of goods are the food and furniture, with the food being crucial for the survival of the people, while the furniture is an essential part of every home and its practicality and decor. Examples of services are teaching and car repairing. The teaching is crucial for the development of the societies, as through it the people get education, while the repairing of cars is very important as lot of people have them, can not afford to buy new ones all the time, and they need for their daily movement over longer distances.
Answer:
The number of oxygen molecules in the left container greater than the number of hydrogen molecules in the right container.
Explanation:
Given:
Molar mass of oxygen, 
Molar mass of hydrogen, 
We know ideal gas law as:
where:
P = pressure of the gas
V = volume of the gas
n= no. of moles of the gas molecules
R = universal gs constant
T = temperature of the gas
∵
where:
m = mass of gas in grams
M = molecular mass of the gas
∴Eq. (1) can be written as:
as: 
So,
Now, according to given we have T,P,R same for both the gases.
∴The molecules of oxygen are more densely packed than the molecules of hydrogen in the same volume at the same temperature and pressure. So, <em>the number of oxygen molecules in the left container greater than the number of hydrogen molecules in the right container.</em>
Answer:
the length of the pipe is 0.85 m or 85 cm
Explanation:
Given the data in the question;
The successive harmonics are; 700 Hz , 900 Hz , and 1100 H
Now, for a closed pipe,
length of pipe (L) = λ/4
Harmonics; 1x, 3x, 5x, 7x, 9x, 11x
1100Hz - 900Hz = 200Hz
⇒ 2x = 200Hz
x = 100Hz ( fundamental frequency )
λ = V/f = 340 /100 = 3.4 m
Now
Length L = λ / 4
L = 3.4 / 4
L = 0.85 m or 85 cm
Therefore, the length of the pipe is 0.85 m or 85 cm
