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Arithmetic, Relational and Logical Operators and Expressions
Published in Subrata Ray, Fortran 2018 with Parallel Programming, 2019
The next program calculates the escape velocity from the earth. The escape velocity is defined as the minimum velocity that a projectile requires to escape from the earth. It is dependent on the mass (m), radius (r) of the earth and the universal gravitational constant G. It is given by sqrt(2.0*G*m/r). program escapeimplicit nonereal::rearth = 6378.0e3, earthm = 5.98e24 ! radius in meter, mass in kgreal::ev, G=6.67300e-11 ! gravitational constantev=sqrt(2.0*G*earthm/rearth)print *,'Escape Velocity - Earth: ', ev/1000.0, 'km/sec'end program escape
Spacecraft Flight Performance
Published in D.P. Mishra, Fundamentals of Rocket Propulsion, 2017
In order to escape the gravitational pull of a planet, the rocket engine must provide sufficient amount of velocity to the vehicle which is known as escape velocity Ves. This escape velocity can be estimated by equating the kinetic energy of the moving body to the work needed to overcome the gravitational force of a planet: 12mVes2=∫RE∞GMmr2dr By integrating and simplifying this equation, we obtain Ves=2GMR Note that the escape velocity decreases with altitude. For the earth, the escape velocity is equal to 11.2 km/s. The escape velocity is equal to √2 time the orbital velocity Vo.
Mathematical formulas from the sciences
Published in Dan Zwillinger, CRC Standard Mathematical Tables and Formulas, 2018
Escape velocity from the Earth’s surface is 11 km/s. $ {\text{km/s}} . $
Optimization of escape routes during mine fire using GIS
Published in Mining Technology, 2023
Mohamed Ali, Ahmed Abd El-Aziz, Mohamed Elwageeh
Ruixin et al. (2018) performed an experiment to study escape velocity. It was carried out on the roadway of the Mu Chengjian Coal Mine. In the experiment, the relationships between the miner's escape velocity and the inclination of the roadway, the area of the accessible section of the roadway, and the average wind velocity of the roadway were obtained through single-factor analysis and two multiple regression equations for the escape velocity were developed through multivariable linear regression analysis. From this experiment, a mathematical model was conducted to be used to predict the miner's escape velocity during mine fire periods under different roadway conditions (Equations (6) and (7)) (Ruixin et al. 2018):
Reinforcement learning for safe evacuation time of fire in Hong Kong-Zhuhai-Macau immersed tube tunnel
Published in Systems Science & Control Engineering, 2018
It can be seen from the numerical experiment that the number of samples in four is , and . Let us say that the escape samples get out from the vehicle after , and . Then they start to escape to the four EXIT doors by the choice given by RL. The escape velocity is ve, and . After time , they arrive exit entrance area. From the second chapter, we know that the ratio flow of the exit is . The flow rate of each exit is . Through time – flow equation: After calculation, people get off and escape to safety spending at least the time , t. Therefore, the minimum safe escape time of the HK-ZH-M immersed tube tunnel is .
New coal-charging method: analysis of force characteristics and velocity distribution of coal particles with dense phase continuous flow in cylinder
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Lowering the blanking height, the concentration of particulate dust in coking chamber was reduced effectively. The effect of blanking height on particle track in Figure 13. The Figure indicate that in the cylinder lifting process, particles escape to both sides and the particle escape velocity near the cylinder coal outlet is the largest. At the end of the whole process, only a few particles pass through the waste gas outlet, and basically no dust escapes from the coal charging hole.