Answer:
gravity
Explanation:
That would make the most sense from what I know
That is potential energy.
Answer:
Gravitational lensing is how we know there is dark matter
What this means is that the light is bending as the light travels from the source to the observer, and if there are any 'holes' in between the beam, that is where 'dark matter' exists
Explanation:
Becuz when you wash up in the tub you want layers of soap so you don’t stink
Answer:
A )
Explanation:
This change in frequency observation occur due to doppler effect
if the wave source moves,In the time between one wave peak being emitted and the next, the source will have moved so that the shells will no longer be concentric. The wavefronts will get closer together in front of the source as it travels and will be further apart behind it. (see the graph)
when the person standing still in front of the ambulance, he will observe a <em>higher frequency </em>than before as the source travels towards them.

The pitch we hear depends on the frequency of the sound wave.
A high frequency corresponds to a high pitch
as we hear a higher frequency , it makes the <em>pitch higher</em> too