Answer:
The Elevator
Explanation:
The frame of reference is the immovable item and remains at the same place and can be used for guiding some one. For example I am telling you an address by saying that you will cross the mega store and then there will a Ferrari and on the next street is my home. So you kept searching my home and then you called me again. I checked from my window before receiving call and saw that the ferrari was gone. So it took more time which means that the frame of reference choosen was movable item. The frame of reference choosen is always immovable. So here I want to move towards elevator which is immovable so choosed it. Furthermore, ship is movable item and the ocean doesn't specify right direction thatswhy stars were used in the ancient times.
Wave interference is the phenomenon that occurs when two waves meet while traveling along the same medium. The interference of waves causes the medium to take on a shape that results from the net effect of the two individualwaves upon the particles of the medium.Hope this help!
When the pump removed the air in the bell, the balloon expanded.
<u>Option: B</u>
<u>Explanation:</u>
In order to construct our own environment in the glass jar known as bell jar system, which can be used to explore and consider our larger environment on Earths, for an instance. Here a glass jar that hinges on an airtight rubber basis i.e seals appropriately. At the top of the jar, a bung is connected to it which passed via a metal tube. It has an adjacent flexible tube that goes to a hand vacuum pump and the best hand-powered pump was made with a wine preserver.
When the pump extracts the air from the bell jar, the pressure inside the balloon naturally decreases. The balloon usually has a air pressure around it, which restricts its size, but when this air is extracted and the pressure around it decreases the gas in the balloon will expand and the balloon seems to be inflating. When you release the air back into the bell jar, it will once again compress back to its actual size.
The independent variable is the different amount of repellent each person is given. This is because it does not depend on any variable. The dependent variable is what they are measuring, which would be the number of bites on each volunteer.
I hope this helps! :)