Answer:
<h2><em><u>C. It must reflect red light wavel</u></em></h2>
Explanation:
<em>The color of the object is reflected by the object other colors are absorbed by the object.</em>
Here <em>object appears in red color so red color is reflected by the object and other colors are absorbed.</em>
Answer:
The pitch that he hears after the truck passes and is moving away is 819.6 Hz.
Explanation:
The pitch that he hears after the truck passes and is moving away can be calculated using the following equation:

Where:
: is the perceived frequency
: is the emitted frequency
: is the speed of sound = 340 m/s
: is the speed of the observer = 0 (he is not moving)
: is the speed of the fire truck
First, we need to find the speed of the fire truck. When it approaches the observer we have:




Hence, the speed of the fire truck is 25.05 m/s.
Now, we can calculate the pitch that the observer hears after the truck passes:



Therefore, the pitch that he hears after the truck passes and is moving away is 819.6 Hz.
I hope it helps you!
Rutherford's nuclear model stated that a cloud of negative electrons surround the nucleus however scientists realized that electrons in a cloud around the nucleus of an atom would be attracted to the nucleus, causing the atom to collapse. Thus Bohr's model proposed that electrons were contained in shells and they orbit the nucleus at fixed distances.