Answer:
20 parts
Step-by-step explanation:
7:5
28:x
7*4=28, 5*4=20; x=20
28:20
Answer:
A Pipe that is 120 cm long resonates to produce sound of wavelengths 480 cm, 160 cm and 96 cm but does not resonate at any wavelengths longer than these. This pipe is:
A. closed at both ends
B. open at one end and closed at one end
C. open at both ends.
D. we cannot tell because we do not know the frequency of the sound.
The right choice is:
B. open at one end and closed at one end
.
Step-by-step explanation:
Given:
Length of the pipe, = 120 cm
Its wavelength = 480 cm
= 160 cm and = 96 cm
We have to find whether the pipe is open,closed or open-closed or none.
Note:
- The fundamental wavelength of a pipe which is open at both ends is 2L.
- The fundamental wavelength of a pipe which is closed at one end and open at another end is 4L.
So,
The fundamental wavelength:
⇒
It seems that the pipe is open at one end and closed at one end.
Now lets check with the subsequent wavelengths.
For one side open and one side closed pipe:
An odd-integer number of quarter wavelength have to fit into the tube of length L.
⇒ ⇒
⇒ ⇒
⇒ ⇒
⇒ ⇒
So the pipe is open at one end and closed at one end
.
Answer:
answer is 90 for first term
Step-by-step explanation:
Let the terms be
First term x
We will use the formula s∞=x/1−r to find the sum of an infinite geometric series, where −1<r<1.
We know the sum and the common ratio, so we'll be solving for x where r =4/5
s∞=x/1−r
450=x/1−4/5
450=x/1/5
450=5x
x=90
this is the first term x1 = 90
we know that common ratio is 4/5, so multiplying the first term by factor 4/5 to get the second term
90 x 4/5= 72 second term
Answer:
E. 2, 3, 4
Step-by-step explanation:
The sum of the shortest two sides must exceed the longest side. That is only the case for the set ...
{2, 3, 4}
Answer:
AC+CB=AB
Step-by-step explanation:
Let's see.... If you are a visual learner this could help.
So you can see that C is right in between them so the distance between AC and the distance between CB would equal the whole line AB. So if you add AC and CB you would get AB.