When dealing with multiple forces acting on a body, it is advisable to draw a free-body diagram like that shown in the picture. There are four forces acting on the box: weight (W) pointing straight down, normal force perpendicular to the slope denoted as Fn, force used to push the box upwards along the slope and the frictional force acting opposite to the direction of motion of the box denoted as Ff. Frictional force is equal to coefficient of kinetic friction (μk) multiplied with Fn.
∑Fy = Fn - mgcos30° = 0
Fn = (50)(9.81)(cos 16) = 471.5 N
When in motion, the net force is equal to mass times acceleration according to Newton's 2nd Law of Motion:
Fnet = F - μk*Fn - mgsin30° = ma
250 - (0.2)(471.5 N) - (50)(sin 16°) = (50)(a)
a = 2.84 m/s²
The statement 'all energy in the universe is a result of mass being converted into energy' correctly describes mass-energy equivalence.
<h3>What is mass-energy equivalence?</h3>
The expression mass-energy equivalence refers to the proportion of matter that can be converted into energy in the universe.
This mass-energy equivalence is an outcome of process of converting mass into energy.
In conclusion, the statement 'all energy in the universe is a result of mass being converted into energy' correctly describes mass-energy equivalence.
Learn more about mass-energy equivalence here:
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450 J / 3 s = 150 J/s = 150 watts.
Answer:
I believe its C: Secretary of War. I hope this helped :)
Explanation:
Constructive interference in performance halls and the elimination of echoes are reasons why choir concerts better in performance halls than in gymnasiums.
<h3>What is constructive interference?</h3>
Constructive interference is a phenomenon which occurs when two waves travelling in same direction and which are in phase add up together to produce a wave of greater amplitude.
Constructive interference occurs in performance halls while destructive interference occurs in gymnasiums.
Also in performance halls, echoes are minimized due to the padded walls and the curtains while echoes which disturb choir concerts occur in gymnasiums.
Therefore, choir concerts better in performance halls than in gymnasiums because of constructive interference in performance halls and the elimination of echoes.
Learn more about constructive interference and echoes at: https://brainly.in/question/2378717
