A flat line means the the speed is the same . Its moving at the same pace.
Answer:
A-the energy of the wave decreases gradually
Explanation:
when a wave is acted upon by an external damping force the energy of the wave decreases gradually.
The energy degrades into the form of heat which is considered to be of less value and use. The reason is because it disperses and spreads more widely.
So therefore it end up as heat with a little sound but that is close to none because that too disperses into heat i.e. decreased form of energy.
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.