Most likely climbing up the mountain
<span>It can form four covalent bonds. </span>
PHysical properties are properties that do not involve changes in the molecular level. In this case, malleability and magnetism are physical.
Chemical properties involve changes to the substance at the molecular level or change its identity. In this case, reacting with oxygen and nonflammability is a chemical property.
Answer:
The velocity of the police car is, v = 17.798 m/s
Explanation:
Given data,
The actual frequency of the siren, f = 2010 Hz
The observed frequency of siren is, f' = 2120 Hz
The velocity of the observer, v' = 0 m/s
The velocity of the source, v = ?
The formula for Doppler effect,

Where,
V - velocity of sound waves in air.

Substituting the given values,

v = 17.798 m/s
Hence, the velocity of the police car is, v = 17.798 m/s
1)
The connections between neurons in the retina, specifically the connections referred to as “lateral inhibition,” help us see which of the following better?
<em><u>A) Contrast</u></em>
B) Faces
<span>C) Colors
2)
</span>Improving the contrast of an image (making the dark regions darker and the light regions lighter) helps us to identify:
<em><u>A) The edges of objects</u></em>
B) The center of objects
<span>C) The color of an object
</span>
3)
What assumption does our visual system make in order to see curved surfaces (domes, holes)?
<em><u>A) Light comes from above</u></em>
B) Curved surfaces are always evenly lit
<span>C) Curved surfaces are always easy to see, no assumptions are made
</span>
4)
Which part of the face does our brain pay the most attention to?
<u><em>A) Eyes and mouth</em></u>
B) Eyes and ears
<span>C) Eyes and chin
</span>
5)
If all these assumptions sometimes lead to mistakes, for example in these optical illusions, why do we make them?
A) It helps us see things faster
B) It helps us see things correctly
C) It helps us pay attention to what's important
<span><em><u>D) All of the above
</u></em></span>
Hope that helps :)
*the correct answers are bolded, italicized, and underlined.*