# Tag Info

1

I have found mistake in my calculatuion. First j = −(1 + e) vab1 · n j/= 1⁄ma + 1⁄mb + (rap × n)2 ⁄ Ia + (rbp × n)2 ⁄ Ib is how we calculate the impulse. taken from here http://myphysicslab.com/collision.html. the expression (rap × n) is a cross product of vectros, i calcualted it as dot product. and the expression jn is NOT a scalar value. it is ...

1

You're basically looking for a smoothing algorithm, something that takes a collection of points and turns it into a density. This can be done with the help of a kernel, a weighting function $K(u)$ that satisfies the following two conditions: \begin{align} \int_{-\infty}^{+\infty} K(u)\,du=1 \\ K(u)=K(-u)\quad\forall u \end{align} The Wikipedia article I link ...

0

The acceleration seems quite high - but assuming it is correct, you need to take into account that your velocity keeps increasing. The force might be constant at 8.2 kN (please, drop the extra digits. You are estimating the mass of the car: do you know how much the passengers weigh?) but as the velocity changes (from acceleration) so will the power. In ...

5

Enzo is fundamentally a grid-based finite-volume hydrodynamics code. That is, the domain is divided into cells, each is assigned various fluid properties (density, velocity, etc.), and at each timestep fluxes of those quantities across the interfaces between cells are used to update the quantities in the cells. It has a choice of particular methods for ...

1

In a reference frame where the center of mass of the Earth-Sun system is at rest, we will have $$m_\text{Sun} \vec{v}_\text{Sun} + m_\text{Earth} \vec{v}_\text{Earth} = 0 \quad \Rightarrow \quad \vec{v}_\text{Sun} = - \frac{m_\text{Earth}}{m_\text{Sun}} \vec{v}_\text{Earth}.$$ In particular, if this is true at some initial time, then it's true at all ...

Top 50 recent answers are included