Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
Answer:
Our final answer is option (c) that is :
A resonant mode of your vocal tract.
Explanation:
Lets understand pitch of a sound first:
Pitch: Is the rate of vibrations produced and also the degree of lowness and highness of a tone.
Pitch formant:
When we take air inside our vocal tract it oscillates at different pitches depending upon the cast and capacity of the opening of the vocal tract.
Formant comes from the vocal tract and also at a resonance of our vocal tract.
So basically the vocal tract play a vital role for the formant.
Final answer is : A formant is a resonant mode of our vocal tract.
Answer:
B. Smaller than
Explanation:
This question is from the Doppler effect. As the object which is in motion goes off from the other, there's a reduction in the frequency. This is due to the fact that successive soundwave get to be longer. So that the pitch will then be lowered. When the person observing moves towards what is making the sound, each soundwave that follows gets faster than the previous.
Solar power many be a bit pricey, but it is more efficient than coal and it is better for the environment, coal could be made easily and is cheaper, but Solar power is efficient.
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