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bogdanovich [222]
2 years ago
14

Why is it important to use placebos and a double-blind approach in some studies

Physics
1 answer:
viktelen [127]2 years ago
6 0
Another name for these two words is "constant" and you want to have a "constant", because you want something to compare your experimental group to, to see whether data had changed or not. So you have placebos or a double- blind to compare your experimental group to it and also so you know you don't have a bias or anything in the study.
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Two violinists are trying to tune their instruments in an orchestra. One is producing the desired frequency of 440.0 hz. The oth
Katyanochek1 [597]

Answer:

Percentage change in tension is 3.8%

Explanation:

We have given initially frequency f_1 = 440 Hz

Let tension in the string at this frequency is T_1

Now second frequency is f_2=448.4Hz

Frequency in string is given by

f=\frac{1}{2L}\sqrt{\frac{T}{\mu }}

From the relation we can say that

\frac{f_1}{f_2}=\sqrt{\frac{T_1}{T_2}}

\frac{440}{448.4}=\sqrt{\frac{T_1}{T_2}}

{\frac{T_2}{T_1}}=1.038

Percentage change in tension is equal to

=\frac{T_2-T_1}{T_1}=\frac{T_2}{T_1}-1=(1.038-1)\times 100=3.8 %

So percentage change in tension is 3.8%

4 0
3 years ago
an incandescent lightbulb has an efficiency of 2.1% and a power of 60 w. how much light energy does the lighbulb produce in 1 se
AveGali [126]

Explanation:

Power output of the bulb:

0.021 × 60 W = 1.26 W

Energy produced by the bulb in 1 second:

E = Pt

E = (1.26 W) (1 s)

E = 1.26 J

Round as needed.

5 0
3 years ago
What two factors affect the gravitational force between two objects
Marina86 [1]

Answer:

When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them.Explanation:

7 0
3 years ago
Read 2 more answers
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Neko [114]
According to the task there should be the graph that supports Sally's hike, but after looking on the options it seems that Sally doesn't walks at a constant rate and there is the negative option that coincides with my thoughts. So, I bet the false statement is the third option represented in the scale above.
5 0
3 years ago
Choose all the answers that apply. Oxygen is _____. transported by blood picked up in the alveoli released into the air by the l
aleksklad [387]
ANSWER:

- Transported by blood picked up in the alveoli
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Hope this helps! :)
4 0
2 years ago
Read 2 more answers
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