Tutor profile: Sarah W.
Subject: Physics (Newtonian Mechanics)
A car is traveling in the positive x direction at 4 m/s. It takes 5 seconds to slow to a complete stop. What is the magnitude and direction of the car's acceleration during those 5 seconds?
1) GIVEN- what information do we have? Vo= 4 m/s V= 0 m/s t= 5s 2) UNKOWN- what are we solving for? acceleration=? 3) EQUATION-what equation do we know that can help us solve this? a= (v-vo)/t 4) SUBSTITUTE - put known information into the equation. a= (0m/s- 4m/s)/ 5s 5) SOLVE- what is the final answer? a= -0.8 m/s^2 (note that the acceleration is moving in the opposite direction of the velocity because the car is slowing down)
Subject: Basic Chemistry
How do you determine if a element will behave as an anion or a cation?
An anion is a negatively charged ion that is looking to gain a positive charge. Typically anions are found on the right most side of the periodic table (excluding the noble gases). Elements on the right side of the periodic table generally have less than 4 electrons in their valance shell. In order to gain a full, stable valence shell, the element will donate OR share its electrons with a positive ion and drop down an energy level. A cation is a positively charge ion that is looking to gain a negative charge. Typically cations are found on the left side of the periodic table. Elements on the left side of the periodic table generally have more than 4 electrons in their valance shell. In order to gain a full, stable valence shell, the element will gain OR share its electrons with a negative ion and fill out their outermost shell. A good general rule of thumb is that elements with more than 4 valance electrons are cations, and elements with less than 4 valance electrons are anions. It is important to note that transition metals and metalloids can sometimes act as both anions and cations depending on what it is bonding with.
How do Punnett Squares help up determine the probability of traits in offspring?
Punnett Squares are a tool that can be used to determine the probably of traits in offspring. In every chromosome pair there are genes known as alleles. We get one allele from our biology father (sperm) and the other allele from our biological mother (egg). These alleles can either have a dominant or recessive trait attached to them. Traits are seen in humans through phenotypes, or physical appearances. Phenotypes are determined by the genotypes, or allele groupings, of the individual. Typically these are seen through dominant or recessive traits. if an individual is presenting the dominant phenotype, their genotype is homozygous dominant, or heterozygous. A homozygous dominant genotype means that the individual has two dominant allele (one from sperm and one from egg),, where at the heterozygous genotype means that the individual has one dominant and one recessive allele. In most situations the dominant allele will take over and display the dominant phenotype. An individual will display the recessive phenotype if their allele pair is homozygous recessive, containing both recessive alleles. By using a Punnett square, one can essentially cross the chromosomes of two potential offspring to develop the probably of one or more traits. This probability will reset every time a new offspring is formed. This is based on the idea of crossing over during sexual reproduction.
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