Please help I need this fast
2 answers:
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Answer:
5.24 m/s
Explanation:
So for the rod to be able to rise upward to the straight up position, the kinetic energy caused by linear speed v0 must be just enough to convert into the potential energy.
Since the rod is uniform in mass, we can treat the body as 1 point, at its center of mass, or geometric center, aka 0.35 / 2 = 0.175 m from the pivot.
For the rod to swing from bottom to top, the center must have moved a distance of h = 0.175 * 2 = 0.35 m, vertically speaking.
Since we neglect friction and air resistance, according to the law of energy conservation then:
Where v is the speed at the center of mass, g = 9.81 m/s2 is the gravitational acceleration, and m is the mass. We can divide both sides by m
As this is only the speed at the center of mass, the speed at the bottom end would be different, to calculate this, we need to find the common angular speed:
Where r is the rotation radius, or the distance from pivot point to the center of mass
Where R is the distance from the pivot to the bottom end of the rod
The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:
where I is the intensity and r is the distance from the source.
We can assume for instance that the initial distance from the source is r=1 m, so that we put
The intensity at r=3 m will be
Therefore, the sound intensity has decreased by a factor
.
where I is the intensity and r is the distance from the source.
We can assume for instance that the initial distance from the source is r=1 m, so that we put
The intensity at r=3 m will be
Therefore, the sound intensity has decreased by a factor