# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Information about this web site => Request for physics Simulations => Topic started by: shogojiawei on April 10, 2010, 03:16:24 pm

 Title: requesting for simulations for object falling with air resistance/board:26-100- Post by: shogojiawei on April 10, 2010, 03:16:24 pm is there simulations for object falling with air resistance. terminal velocity too. Title: arh... is there simulation for object falling downwards with air resistance??? Post by: shogojiawei on April 10, 2010, 03:33:55 pm i want to check the terminal velocity too ;D Title: ???? is there simulation for objects falling with air resistance??? Post by: shogojiawei on April 10, 2010, 03:53:41 pm just want to noe the terminal velocity and how the object falls Title: Re: requesting for simulations for object falling with air resistance/board:26-100- Post by: Fu-Kwun Hwang on April 10, 2010, 09:22:19 pm The following is a simulation which assume the force acting on the particle with mass m (under gravity g) and drag force b*v2 i.e. F=m*g - b*v2Initially, velocity is zero. The force is maximum, particle starts to accelerate and velocity increase with time.When the drag force is equal to weight of the particle, the net force become zero and the particle starts to fall down with constant speed. i.e. m*g=b*v2, so $v=\sqrt{mg/b}$ is the terminal velocity. Title: Re: requesting for simulations for object falling with air resistance/board:26-100- Post by: Fu-Kwun Hwang on April 11, 2010, 09:15:50 pm What will happen if there are many objects with the same density but different size, all fall from the same height.The terminal velocity $v=\sqrt{mg/b}=\sqrt{\rho Vg/b}$, so the terminal velocity is proportiobal to $\sqrt{V}$ where $V$ is the volume of the object.The following simulation try to illustrate the size effect on terminal velocity.The ratio of the mass for the object is 1:2:3:4:5:6:7:8:9Because it is a 2D simulation, the radius is proportional to $\sqrt{m}$.You can try it with different gravity g , or drag constant (Drag force = bv2)