Recent content by HCD

The region of the ionosphere with highest electron density is where molecules and atoms are being ionized by photons radiated directly from the Sun. Is the rest of the ionosphere staying ionized mainly due to interactions with the free electrons and recombination photons that spread out from...

Here is what I understood so far. In the first instant under consideration the foam has zero velocity relative to the shuttle and a velocity of 2500 ft/s relative to the atmosphere. Still in that instant, the foam is experiencing a force due to gravity as well as drag caused by the relative...

That all makes perfect sense, thanks. But then how would you model the problem?

Okay, let's simplify the problem to 1-dimension and assume that drag due to air flow is constant. Then in the first instant after the foam comes loose from the shuttle the force ## F_0 ## acting on the foam can be modeled as $$ F_0 = mg + \frac{1}{2} \rho (2500 \textrm{ ft/s})^2 C_D A. $$ But as...

Are you saying that drag is what accelerates the foam relative to the shuttle in the first place? That means that in the first instant after the foam comes loose from the shuttle the forces acting on the foam are $$ \boldsymbol{F} = \left[ mg + \frac{1}{2} \rho (2500\textrm { ft/s})^2 C_D A...

The problem is to derive the equations that describe the velocity as well as the distance traveled by the foam as functions of time, but my problem is to model the forces acting on the foam due to the air flow. I was thinking of two possibilities, one where I should model the force due to air...

Homework Statement Problem statement in attached file. Homework Equations [/B] Drag force as a function of velocity for a body immersed in a fluid: $$ \boldsymbol{F}_D = \frac{1}{2} \rho \boldsymbol{v}^2 C_D A, $$ where ## \boldsymbol{F}_D ## is the drag force, ## \rho ## is the density of...