Answer: The fundamental frequency of the slinky = 8Hz
An input frequency of 28 Hz will not create a standing wave
Explanation:
Let Fo = fundamental frequency
At third harmonic,
F = 3Fo
If F = 24Hz
24 = 3Fo
Fo = 24/3 = 8Hz
If an input frequency = 28 Hz at 3rd harmonic
Let find the fundamental frequency
28 = 3Fo
Fo = 28/3
Fo = 9.33333Hz
Since Fo isn't a whole number, it can't create a standing wave
Answer: b) The velocity vector is perpendicular to the acceleration vector; the acceleration vector is parallel to the net force vector.
Explanation: A change in velocity creates an acceleration. As the object rotates through the circular path it is constantly changing direction, and hence accelerating, which causes a constant force to act upon the object. This Force acts towards the center of curvature, directly toward the axis of rotation in a direction parallel to the acceleration of the body along the path. Because the object is moving perpendicular to the force, the path followed by the object is a circular one. Hence the velocity of the object is perpendicular to the acceleration.
Answer:
A sample of 5.2 mg decays to .65 mg or to 1/8 of its original amount.
1/8 = 1/2 * 1/2 * 1/2 or 3 half-lives.
3 * 30.07 = 90 yrs for 5.2 mg to decay to .65 mg
You can get these other numbers similarly:
5.2 / .0102 = 510 requires about 9 half-lives which is 30 * 9 = 270 yrs
The first question has the answer to your problem! I found the answer key!
