Proceed at your own pace, because of terminal velocity

2020 ◽  
pp. 109-112
Author(s):  
Susan D'Agostino
Keyword(s):  
Terminal Velocity ◽  
Mathematics Students ◽  
Short Introduction ◽  
Air Resistance ◽  
The Moment

“Proceed at your own pace, because of terminal velocity” offers a short introduction to the mathematics behind terminal velocity—the speed at which the force of air resistance equals the force of gravity on that object. The discussion is illustrated with hand-drawn sketches. Mathematics students and enthusiasts are encouraged to find their own metaphorical terminal velocity in mathematical and life pursuits—the moment at which the force of resistance they encounter matches the force they are able to expend. At the chapter’s end, readers may check their understanding by working on a problem. A solution is provided.

Particle motion with air resistance

2012 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Gy. Sitkei
Keyword(s):  
Basic Equation ◽  
Initial Conditions ◽  
Equation Of Motion ◽  
Terminal Velocity ◽  
Dimensionless Form ◽  
Wood Industry ◽  
Acceptable Error ◽  
General Validity ◽  
Practical Applications ◽  
Air Resistance

Motion of particles with air resistance (e.g. horizontal and inclined throwing) plays an important role in many technological processes in agriculture, wood industry and several other fields. Although, the basic equation of motion of this problem is well known, however, the solutions for practical applications are not sufficient. In this article working diagrams were developed for quick estimation of the throwing distance and the terminal velocity. Approximate solution procedures are presented in closed form with acceptable error. The working diagrams provide with arbitrary initial conditions in dimensionless form of general validity.

SIMULATION OF DOOR MOVEMENT WITH A CLOSING MECHANISM

2021 ◽  
Vol 2021 (11) ◽  
pp. 4-10
Author(s):  
Aleksandr Reutov
Keyword(s):  
Mechanical Characteristics ◽  
Dynamic Models ◽  
Quality Criteria ◽  
Strong Impact ◽  
Closing Time ◽  
Door Opening ◽  
Air Resistance ◽  
The Moment ◽  
Moment Of Resistance ◽  
Closing Mechanism

The work objective is to determine the parameters of the closing mechanism that provide the specified characteristics of the door movement. Research method: computer simulation of the movement of a door with a lock mechanism as a multi-mass dynamic system, taking into account the mechanical characteristics and contact interaction of the lock mechanism. Research results and novelty. Computer dynamic models of a door with a door closer and a door with a spring have been developed. The moments of the door opening force, the closing time of the door, the angular velocity of the door at the time of impact with the frame are considered as the criteria for the quality of the door closing mechanism. Formulas are obtained that determine the permissible values of stiffness and deformation of the door closer spring according to the specified moments of the door opening force. The movement of doors with a door closer and with a spring is compared. The parameters of the closing mechanism providing the specified characteristics of the door movement of the considered example are determined. It is shown that with the same values of the opening force moments, the speed of impact with the frame in the case of the door closer is less than the door with a spring. Conclusions: The developed computer dynamic models of a door with a door closer and a door with a spring make it possible to determine the characteristics of the door movement taking into account the inertial and mechanical characteristics of the door closer and spring mechanisms. The permissible values of stiffness and deformation of the door closer spring can be determined by the specified moments of the door opening force in two positions. It is established that the forces of air resistance and friction in the hinges of the door cannot create the moment of resistance necessary for smooth closing of the door without a strong impact on the frame with a limited closing time. The quality criteria that minimize the closing time and the speed of impact of the door with the frame are contradictory. The choice of optimal parameters of the door closing mechanism is possible if one of the criteria is replaced by a restriction. The developed formulas and computer models are recommended for use in the design of devices that restrict the movement of doors.

Research on the Flight Status of Badminton Based on the Method of Mechanics Analysis

2012 ◽  
Vol 507 ◽  
pp. 246-251
Author(s):  
Xiao Liang Xie ◽  
Kun Jiang
Keyword(s):  
Research Method ◽  
Terminal Velocity ◽  
Measured Data ◽  
Motion Equation ◽  
Movement Trajectory ◽  
Flight Trajectory ◽  
Motion Equations ◽  
Air Resistance ◽  
Mechanics Analysis ◽  
The Relationship

The main purpose of this research is to establish and validate the flight movement equation of a badminton, and found the relationship between the velocity of badminton and the air resistance. The research method is based on the motion laws of aerodynamics,which establish a motion equation of flight trajectory under the influence of the gravity and air resistance by applying the theory of aerodynamics. The results show that the motion equations of flight trajectory of a badminton can be determined through the structure of terminal velocity,and the measured data is quite good fitting with the prediction of badminton movement trajectory. Findings also show, the resistance is proportional to the square of the badminton's speed. In addition, the angle and intensity of the wind may affect the trajectory.

scholarly journals Kinematics and dynamics of an incomplete circular wheel drive of an agricultural tractor

2021 ◽  
Vol 935 (1) ◽  
pp. 012030
Author(s):  
Yu Kazakov ◽  
V Medvedev ◽  
V Batmanov ◽  
V Pavlov
Keyword(s):  
Tangential Force ◽  
Experimental Studies ◽  
Planetary Gearbox ◽  
Radial Stiffness ◽  
Wheel Drive ◽  
Air Resistance ◽  
Order Of Magnitude ◽  
The Moment ◽  
Wheel Radius ◽  
Main Influence

Abstract The disadvantage of wheeled tractors is soil compaction, slipping due to limited traction, low tangential force. Experimental studies of a tractor with incomplete circular wheel mover on stubble, sand and virgin snow showed an increase in cross-country ability, a decrease in skidding, an increase in traction, and an increase in productivity. The purpose of the study is to develop a methodology for kinematic and dynamic analysis of incompletely rounded wheel propellers with a built-in differential. The equation of motion of the wheel is obtained on the basis of two-stage overcoming by the wheel of a single threshold obstacle taking into account the longitudinal and radial stiffness of the tire, its deformation, air resistance in the tire. The main influence is provided by translational speed, wheel radius and radial stiffness, the moment of inertia of the wheel and the shoulder of the application of mass. Planetary gearbox proposed in which the shaft of the driving satellite is a bearing, while the radius of the gear is an order of magnitude smaller than the radius of the wheel. The direction of improvement of wheel mover, increasing their traction properties is justified.

scholarly journals Some Workout Problems on Motion of Raindrop

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Sneha Dey ◽  
Amitava Ghorai
Keyword(s):  
Mathematical Modeling ◽  
Close Agreement ◽  
Classical Problem ◽  
Terminal Velocity ◽  
Air Resistance ◽  
Rain Drop

The motion of rain drop through atmosphere is an interesting classical problem because of the fact that air resistance and moisture accretion are integral part of it. Mathematical modeling of it using Newtonian formalism is considered here and discussions are made for no mass accretion and air resistance proportional to nth power of velocity. We use python program and library extensively to find the terminal velocity of rain drop. Graphs show close agreement and velocity power up to n=3 is good.

scholarly journals Flow Field around the Badminton Shuttlecock during Flipping Motion

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuki Sakurai ◽  
Kenichi Nakagawa ◽  
Hiroaki Hasegawa
Keyword(s):  
Flow Field ◽  
Initial Velocity ◽  
Terminal Velocity ◽  
Wind Tunnel Experiments ◽  
Aerodynamic Stability ◽  
Racquet Sports ◽  
Aerodynamic Properties ◽  
Unique Shape ◽  
Aerodynamic Property ◽  
The Moment

Badminton is one of the most popular sports in the world. The shuttlecock is used in badminton game has the unique shape. The shuttlecock is truncated cone-shaped and consists of a cork, gaps and a skirt portion. The shuttlecock has aerodynamic properties which differ from the ball used in other racquet sports. As an example of unique aerodynamic property, the shuttlecock shows high deceleration. It is known that the initial velocity immediately after smashing may reach up to 137m/s (493 km/h) at maximum. The velocities of the shuttlecock are reduced from the initial velocity of 67 m/s to the terminal velocity of approximately 7 m/s for approximately 0.6 s (Hubbard et al. 1997). In addition, turnover refers to the flipping experienced by a shuttlecock when undergoing heading change from nose pointing against the flight path at the moment of impact and a shuttlecock indicates the aerodynamically stable feature for the flip movement just after impact (Cohen et al. 2015). The turnover stability of a series of feather and synthetic shuttlecocks was measured to compare the performance of synthetic shuttlecocks to that of feather shuttlecocks (Calvin et al. 2013). The turnover stability of the shuttlecock is investigated through experiment and simulation, and the angular response of the shuttlecock in turnover was modelled and studied (Calvin et al. 2015). Furthermore, it was reported that the aerodynamic stability of the shuttlecock during flip movement was affected by gaps of the shuttlecock skirt in a previous study (Nakagawa et al. 2017). However, the mechanism of turnover stability of the shuttlecock has not been fully understood. The purpose of this study is to investigate the unsteady flow field around the shuttlecock during flip movements. In the present, we simulated the flipping motion by wind tunnel experiments and visualized the flow field around the shuttlecock by a PIV technique.

Planetary Systems: A Very Short Introduction

2021 ◽  
Author(s):  
Raymond T. Pierrehumbert
Keyword(s):  
Solar System ◽  
Planetary System ◽  
Planetary Systems ◽  
Time And Space ◽  
Short Introduction ◽  
The Moment ◽  
New Generation

Planetary Systems: A Very Short Introduction takes the reader on a journey through time and space, exploring how planetary systems such as ours form and evolve, and the conditions under which life may arise. Not long ago, the Solar System was the only example of a planetary system that we knew. Now, we know of thousands of planetary systems, and have even been able to observe the moment of their birth. This VSI reveals the astonishing variety of planetary systems out there. It explores the insights gained about these other worlds from a new generation of telescopes.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

Pinocytotic-Like Forms of Mitochondria From Rat Anterior Pituitary

1968 ◽  
Vol 26 ◽  
pp. 146-147
Author(s):  
Burton B. Silver
Keyword(s):  
Electron Micrographs ◽  
Conformational Changes ◽  
Anterior Pituitary ◽  
Dynamic State ◽  
Surrounding Cell ◽  
The Matrix ◽  
The Moment ◽  
Cell Medium ◽  
Sectioned Tissue ◽  
State Of Activity

Sectioned tissue rarely indicates evidence of what is probably a highly dynamic state of activity in mitochondria which have been reported to undergo a variety of movements such as streaming, divisions and coalescence. Recently, mitochondria from the rat anterior pituitary have been fixed in a variety of configurations which suggest that conformational changes were occurring at the moment of fixation. Pinocytotic-like vacuoles which may be taking in or expelling materials from the surrounding cell medium, appear to be forming in some of the mitochondria. In some cases, pores extend into the matrix of the mitochondria. In other forms, the remains of what seems to be pinched off vacuoles are evident in the mitochondrial interior. Dense materials, resembling secretory droplets, appear at the junction of the pores and the cytoplasm. The droplets are similar to the secretory materials commonly identified in electron micrographs of the anterior pituitary.

Advances in Stem Instrumentation for Biology

1990 ◽  
Vol 48 (1) ◽  
pp. 362-363
Author(s):  
J. S. Wall
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Carbon Films ◽  
Specimen Preparation ◽  
Material Deposition ◽  
Active User ◽  
Percent Improvement ◽  
Scanning Transmission ◽  
The Moment ◽  
Film Substrate ◽  
High Level

The forte of the Scanning transmission Electron Microscope (STEM) is high resolution imaging with high contrast on thin specimens, as demonstrated by visualization of single heavy atoms. of equal importance for biology is the efficient utilization of all available signals, permitting low dose imaging of unstained single molecules such as DNA.Our work at Brookhaven has concentrated on: 1) design and construction of instruments optimized for a narrow range of biological applications and 2) use of such instruments in a very active user/collaborator program. Therefore our program is highly interactive with a strong emphasis on producing results which are interpretable with a high level of confidence.The major challenge we face at the moment is specimen preparation. The resolution of the STEM is better than 2.5 A, but measurements of resolution vs. dose level off at a resolution of 20 A at a dose of 10 el/A2 on a well-behaved biological specimen such as TMV (tobacco mosaic virus). To track down this problem we are examining all aspects of specimen preparation: purification of biological material, deposition on the thin film substrate, washing, fast freezing and freeze drying. As we attempt to improve our equipment/technique, we use image analysis of TMV internal controls included in all STEM samples as a monitor sensitive enough to detect even a few percent improvement. For delicate specimens, carbon films can be very harsh-leading to disruption of the sample. Therefore we are developing conducting polymer films as alternative substrates, as described elsewhere in these Proceedings. For specimen preparation studies, we have identified (from our user/collaborator program ) a variety of “canary” specimens, each uniquely sensitive to one particular aspect of sample preparation, so we can attempt to separate the variables involved.

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