Answer:
Photopolymerization is the term for hardening or curing the sealant or composite material by exposing the material to a curing light
Explanation:
It the process through which a photopolymer reacts to the radiations in presence of the Ultra-violet light. Photopolymers refers to those materials and liquid or the plastic resins that are hardened in presence of light source such as the lasers or the lamps. When these materials are irradiated, they undergo chemical reactions and they are hardened and become solid, and hence the process called photopolymerization. Photopolymerization is majorly used in the coating and printing industries and in also in dentistry to fill the top of teeth and prevent the cavities
<h2><u>FORMAT</u><u>ION</u></h2>

Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova. When this dust cloud collapsed, it formed a solar nebula—a spinning, swirling disk of material

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Answer: 0.17hp
Explanation:
Power output = power input × 85%
Power output = power input × 0.85
Power input = IV/0.85
Power input = 9×12/0.85
Power input = 108/0.85
= 127.058 watts
Converting to horse power = 127.058W × 1horse power/745.7W
= 127.058 × 0.001341
= 0.17hp
Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".
Explanation:
Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.
Pitch depends on the frequency. if the frequency increases then pitch increases.
When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.
In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.