# Tag Info

### Time of a ball going up and down with air resistance

In addition to the gravitational force, we now have the drag force. On the way up, both these forces act downward. So the ball experiences an increased net acceleration. This implies that the ...

### Calculating aerodynamic forces on a random object

Aerodynamic numerical simulations are very expensive, too expensive to run in real time. A possible approach If it's good enough, I'd suggest to use a flight dynamics approach, equation of motion of a ...
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1 vote

### General solution for the motion of a 1D particle with drag

For what it is worth, any autonomous 1D 2nd-order ODE $\ddot{x}=a(x,\dot{x})$ can be written as an autonomous 2D 1st-order ODE \begin{align}\dot{x}~=~&v,\cr \dot{v}~=~&a(x,v),\end{align} ...
• 205k

### Is the drag coefficient linear with speed?

The drag coefficient is not linear with speed because of the drag-force formula, $$F_d = C_d A \frac{\rho V^2}{2}$$ where, $F_d$ is the drag force in newtons, $A$ is the cross sectional area of the ...

### How do you convert the damping coefficient to speed dependent drag coefficient (for low speeds)?

I'll assume here that you're dealing with something like a mass-damper-spring system, governed by equation $$m \ddot{x} + k x = f^e + f^{drag} \ .$$ The behavior of a fluid is usually largely ...
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### Investigation Results of Damping of A Spring Showing Changing Phase Angle? Why?

Note: $$\cos(\omega_dt + (\phi_0 + Bt)) = \cos(\omega't+\phi)$$ with $$\omega' = \omega_d + B$$ so your damped frequency is wrong. So look at the above answer regarding error propagations, since ...
• 34.9k
Accepted

### Investigation Results of Damping of A Spring Showing Changing Phase Angle? Why?

Welcome to the experimental world! To be fair, it's quite normal that oscillations do not perfectly coincides after some periods. You have a period of the oscillation $T \simeq 0.7 \, s$ and a shift (...
• 9,802

### Investigation Results of Damping of A Spring Showing Changing Phase Angle? Why?

I think this is just because there isn't going to be perfect agreement between the frequency in your fit function and the real-life frequency. Below are two sine functions that differ in frequency by ...
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### Is it necessary that a particle attains terminal velocity?

No, the ball can never exactly attain its terminal velocity. As the speed of ball increases, the viscous force also increase. So, as the ball gains velocity, its net force will decrease because net ...
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Yes. The force of gravity is constant as an object falls. A drag force gets bigger when the object falls faster. A falling object typically starts at speed $0$. There is no drag force at this speed. ...
In a simplified model such at drag being proportional to the speed $v$ or the squared speed $v^2$ the speed never reaches terminal velocity in general. Rather, it approaches the terminal velocity as \$...