10 POINTS !!! Why is it risky to build something whose natural frequency can be matched byexternal vibrations?
It is risky to build something whose natural frequency is matched with external vibrations because of ; The effect of resonance
When an object constructed has a natural frequency which is equal to the frequency of a nearby external vibration, the amplitude of the vibration of the object will increase due to the resonance effect which occurs because the external frequency matches up with the natural frequency of the constructed object.
The negative effect of resonance is the increase in the amplitude of the vibration of the object which might lead to the partial or complete collapse of the constructed object.
Hence we can conclude that It is risky to build something whose naturalfrequency is matched with external vibrations because of ; The effect of resonance
Answer:Most objects have at least one natural frequency of vibration. If a nearby object vibrates at the same frequency, it can cause resonance. Resonance is an increase in amplitude of a vibration that occurs when external vibrations match an object's natural frequency.
J and K want to have a baby, but they are a little concerned because they both have the sickle cell trait. They want to know what the possibility is that their child may actually have the disease. 1. Develop a Punnett square depicting the possibility that their offspring will have the trait and/or the disease.
2.How would the nurse interpret this Punnett square?
Sickle cell anemia is an autosomal recessive disorder. For the trait to occur, both of the alleles in an individual should be recessive. Parents who both have sickle cell anemia will have 100% results for their children to carry the disease. The results can be depicted from the following punnet square:
s ss ss
s ss ss
The results will be interpreted by the nurse as having 100% chance for the parents to have the child born with sickle cell as both the parents carry the disease which is autosomal recessive.
What does the presence of these coral fossils suggest about the location of North America 370 million years ago?
These fossils indicate that North America must have had a much warmer (i.e a tropical environment 370 million years ago)
Corals are marine animals whose skeletons are easily fossilized and thus have an extensive fossil record. There are many fossils of extinct corals in North America. For example, Lophophyllum is a North American extinct genus of corals dated at 320 million to 290 million years ago (i.e., from the Late Carboniferous period). In general, corals live in warm seawater, and thereby their fossil records can be used as indicators of environmental conditions.
The coral fossils' presence suggests that North America was located near the equator 370 million years ago, within the subtropical climate zones where corals thrive the most.
These seasonal changes in density create growth rings, similar to those found on trees. Scientists can use these rings and other features to determine the climatic conditions during the growing season of the coral.
By comparing the soil and plant and animal evidence at a site, scientists can get a general idea of what the environment was like in the past. By comparing living plant and animal evidence to these ancient remains, scientists can get an idea of what the environments were like.
To learn more about the subtropical climate, refer to the link:
Once a neuron is stimulated and the membrane potential is depolarized, the depolarized axonal membrane is helped to return to its resting potential by opening voltage-gated K+ channels, allowing K+ to flow out of the cell down its concentration gradient.(a) True (b) False
The cell membrane separates the cell from the outer environment. The extracellular fluid contains the sodium ions (Na+), chloride ions (Cl-), while intracellular fluid contains potassium (K +) and negative anions.
The potential difference arises when the membrane is selectively permeable to some ions. The resting potential is -70mV.
When the neurons get excited, the sodium ions start to enter by sodium channels.
Now there are more positive ions inside the cell membrane. It disturbs the resting potential i.e. -70mV. This stage is known as depolarization.
When the inside environment of the cell is more positively charged, the potassium ions start to move out of the cell. It goes out by the voltage-gated channels. Thus resting stage is maintained and it is known as repolarization.
But the initial stability of the cell membrane has to be maintained. To restore the resting stage, the sodium ions start to move out of the membrane and potassium ions enter into the cells again. This is an active transport and has done by the Na+ - K+ pump. Here 3 sodium ions move out and 2 potassium ions pumped into the cell through the plasma membrane.
Thus the resting potential regains. The potassium ions come back into the cells against the concentration gradient and ATP provides the energy for this phenomena.
Neuron or nerve cell may be defined as the structural and functional unit of the nervous system. The neurons conduct the nerve impulse and helps in the transmission of signals.
The depolarization of the cell occurs due to the influx of sodium ions into the cell. For the cell membrane to be in resting potential, the potassium ions moves inside the cell from outside the environment and not out of the cell of the organism.
Thus, the correct answer is option (b).
Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk?
According to the ten percent rule of energy transfer, whenever energy is transferred from one trophic level to a higher trophic level only 10% of total energy available at the lower level gets transferred to a higher one.
Therefore, when the energy is transferred along with the food chain:
grass → grasshopper → mouse → snake → hawk, from grass to hawk there is a loss of 10% of energy at each level.
Therefore, the hawk only gets 0.01% of the energy from the grass.
The best answer is Grass. The grass is photosynthetic, which means grasses make their energy from the sun. About 10% of this total energy is available to other organisms in the food chain.
The difference between the cellular make-up of a living organism and an aluminum can is the
the ability to use energy
Which of these fields of study would be the most useful for someone whowants to examine the effects of deforestation on native species? A. Ecology B. Chemistry C. Meteorology D. Geophysics
Ecology, the definition of ecology is most summed up by studying organisms and their surrounding and how it effects them