Category: Physics

How do Rockets make thrust? Thrust is generated by the propulsion system of the rocket through the application of Newton’s third law of motion; For every action there is an equal and opposite re-action. The re-action to the acceleration of the working fluid produces the thrust force on the engine. How dangerous is rocket fuel? […]

Which of the following is the hardest type of pollution to regulate? The U.S. Environmental Protection Agency (EPA) has identified six criteria pollutants: carbon monoxide, nitrogen dioxide, sulfur dioxide, ozone, lead, and particulates (aerosols). Of these six pollutants, ozone has proved the most difficult to control. Which of these sources of pollution is most difficult […]

What is the difference between the isotopes CL 35 and CL 37? Chlorine-35 and chlorine-37 are both isotopes of the element chlorine. An atom of chlorine-35 contains 18 neutrons (17 protons + 18 neutrons = 35 particles in the nucleus) while an atom of chlorine-37 contains 20 neutrons (17 protons + 20 neutrons = 37 […]

What is the food of amoeba? The food sources of amoebae vary. Some amoebae are predatory and live by consuming bacteria and other protists. Some are detritivores and eat dead organic material. Amoebae typically ingest their food by phagocytosis, extending pseudopods to encircle and engulf live prey or particles of scavenged material. Which kingdom is […]

Is a 60 a passing grade? In fact, a “D” is considered passing in both high school and college, as it’s above 60%. While a passing grade may be as low as 60%, you will want to aim higher for many reasons. As a college student, you don’t want to aim to barely pass a […]

Is a spontaneous reaction negative or positive? A spontaneous reaction is one that releases free energy, and so the sign of ΔG must be negative. Since both ΔH and ΔS can be either positive or negative, depending on the characteristics of the particular reaction, there are four different possible combinations. What characterize a spontaneous process? […]

What is slip percentage? Slip ratio is a means of calculating and expressing the slipping behavior of the wheel of an automobile. The difference between theoretically calculated forward speed based on angular speed of the rim and rolling radius, and actual speed of the vehicle, expressed as a percentage of the latter, is called ‘slip […]

Can the wave function be zero? The wavefunction of a particle can be zero at certain points. Places where the wavefunction is zero are called “nodes”. If the wavefunction is zero at some point, it implies that the probability density at that position is zero. What is the definition for probability? 1 : the quality […]

Why are there multiple codons for the same amino acid? The genetic code is redundant, so that several codons represent the same single amino acid, but there are no ambiguities. There are no examples of a single codon within any genome that represents more than one amino acid. How do I remember my amino acids […]

What are the laws of electrical charges? According to Coulomb, the electric force for charges at rest has the following properties: Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two […]