metallic
hydrogen
ionic
Answer:
This is the answer ˋ( ° ▽、° ) (☞゚ヮ゚)☞ Hope it helps. :)
Explanation:
Answer:
Initial velocity: approximately .
Time taken before return to initial height: approximately .
(Assumptions: ; air resistance is negligible.)
Explanation:
Under the assumption, acceleration of the helmet would be constantly .
During the interval between being thrown upward and reaching maximum height:
Apply the following SUVAT equation to find initial velocity :
.
(Round to three significant figures for the final result, but keep more significant figures for intermediary values.)
In other words, the velocity of the helmet was approximately immediately after the person threw the helmet upward.
Right before returning to the initial height, the velocity of the helmet would be the opposite of its initial velocity: .
The change in velocity would be:
.
(Rounded to three significant figures.)
The initial speed of the helmet was 10.7 m/s and it was in the air for a total of 2.18 s.
This problem involves concept from physics specifically kinematics. Kinematics helps us study the motion of objects. To solve this problem, we need to use the second equation of motion: v²=u²+2as. In this case, the final speed (v) is 0 (when the helmet reaches the highest point, its velocity becomes 0), acceleration (a) is -9.8 m/s² (gravity acts downwards), and the distance (s) is 5.8 m.
Plugging in these values we get: 0 = u² - (2 * 9.8 * 5.8). Solving for u (initial velocity), we get u = √(2 * 9.8 * 5.8) = 10.7 m/s. This is the initial speed of the helmet when it left your hands.
To find out how long the helmet was in the air, we can use the first equation of motion: v = u + at. Solving for t (time), we get: t = (v - u) / a = (0 - 10.7) / -9.8 = 1.09 s going up. Because the time going up and coming down is the same, the total time the helmet was moving is 2 * 1.09 = 2.18 s.
#SPJ2
B. Not at all
C. Destructively
D. A little bit
The dark fringes that appear represent where the waves interfere
C. Destructively
Explanation:
Interference is a phenomenon typical of waves, that occurs when two waves meet at a certain point in space. The amplitude of the resultant wave can be found by using the principle of superposition, which states that the displacement of the resultant wave is the sum of the displacements of each wave. In particular, there are two extreme cases that can occur:
- Constructive interference: this occurs when the two waves meet in phase - i.e., the crest of one wave meets with the crest of the other wave. In this case, the amplitude of the resultant wave is twice the amplitude of each wave.
- Destructive interference: this occurs when two waves meet in anti-phase - i.e, the crest of one wave meets with the trough of the other wave. In this case, the amplitude of the resultant wave is equal to the difference between the two amplitues (and if the two waves have same amplitude, the resultant amplitude will be zero).
This phenomenon can occur also with light wave (which is a type of wave), and it leads to:
- The presence of bright fringes in case of constructive interference
- The presence of dark fringes in case of destructive interference
Therefore, the correct answer is
C. Destructively
Learn more about waves:
#LearnwithBrainly
Answer:
When demonstrating the interference of light waves, the dark fringes that appear represent where the waves are destructively interfere destructively.
Explanation:
The bright lines symbolize constructive interference and some dark lines symbolize destructive interference.
Therefore the correct answer is option C
To learn more about interface waves, refer: