Category: Physics

What did people use before toothpaste? Before modern-day toothpaste was created, pharmacists mixed and sold tooth cream or powder. Early tooth powders were made from something abrasive, like talc or crushed seashells, mixed with essential oils, such as eucalyptus or camphor, thought to fight germs. Did Victorians brush their teeth? Victorian Oral Hygiene & Dental […]

How much sex does a man need? The majority of adult men under 60 think about sex at least once a day, reports Laumann. Only about one-quarter of women say they think about it that frequently. As men and women age, each fantasize less, but men still fantasize about twice as often. What are the […]

How do you write a hypothesis for a two tailed test? Hypothesis Testing — 2-tailed test Specify the Null(H0) and Alternate(H1) hypothesis. Choose the level of Significance(α) Find Critical Values. Find the test statistic. Draw your conclusion. How do you know if a hypothesis is one-tailed or two tailed? A one-tailed test has the entire […]

What can a Punnett square tell you? A Punnett square is a chart that allows you to determine the expected percentages of different genotypes in the offspring of two parents. A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes. What is the purpose of […]

Can I melt glass with a propane torch? You can melt glass with a propane torch only if you can achieve high enough temperature i.e. by creating non-luminous flame. To get a non-luminous flame you have to have some kind of air vent on your torch to let the air mix with the propane which […]

What are 4 principles of informed consent? There are 4 components of informed consent including decision capacity, documentation of consent, disclosure, and competency. Doctors will give you information about a particular treatment or test in order for you to decide whether or not you wish to undergo a treatment or test. What are the 8 […]

How often do solar panels need servicing? To ensure that they operate to their optimum capacity it’s best to get them cleaned a few times a year. There are several options when it comes to cleaning solar panels: Use a solar panel cleaning company. Do you regret getting solar panels? there’s never been a single […]

What are the 3 basic units of measurements? The three most common base units in the metric system are the meter, gram, and liter. The meter is a unit of length equal to 3.28 feet; the gram is a unit of mass equal to approximately 0.0022 pounds (about the mass of a paper clip); and […]

What is scalar value series? If data is a scalar value, an index must be provided. The value will be repeated to match the length of index. #import the pandas library and aliasing as pd import pandas as pd import numpy as np s = pd. Series(5, index=[0, 1, 2, 3]) print s. Its output […]

Why is a system not 100% efficient? It is not possible to have an efficiency of greater than 1 or an efficiency percentage greater than 100%. This would mean that more energy is being transferred than is being supplied, which would mean that energy is being created. This would break the law of conservation of […]