They are a variable that changes as a result of the changes in the manipulated variable
Answer:

I guess you can round it to 11 seconds.
Explanation:
Going with a speed 9m/s means you are going 9 meters in each second.
If you are going 9 meters in second how many seconds will it take to 100 meters?
Visually;
9 meters - - - 1 second
100 meters - - - ?seconds.
When you write like this 9 times ?seconds equal to 100 meters time 1 second. (you probably know this but just in case)
So to find ?second you multiply 100meters by 1 and divide it by 9 whixh will give you 11.1111 seconds whixh again I believe you can round it to 11.
(Kind of a) Proof;
If 9m * ?sec = 100 m * 1 sec
you send 9 meters to other side.
?sec = (100 m * 1 sec) ÷ 9m
Hope it was clear and it helps! Please let me know if you have any questions.
The bulbs will produce lesser light than their capacity, In short they will be dimmer because the the energy will get divided in the number of bulbs.
Answer:
The "2" tells us that there are 2 hydrogen atoms in this compound.
Explanation:
Answer:
It is used in MRI because it does not damage cells
Radio waves are used for space research because they have very long wavelengths
Explanation:
Many parts of the electromagnetic spectrum are applied in clinical diagnosis and treatment of illnesses. However, these highly ionizing radiation damage cells and its dosage must be carefully managed to avoid creating radiation related health problems for the patients.
Radio waves can be used in MRI without issues because the energy of the radiation is not sufficient to cause damage to cells but is sufficient to provide images for the sake of medical diagnosis.
Secondly, radio waves have long wavelength. This property is suitable for long range
communication. Hence it can be used in space research