A stone dropped from a cliff takes 3.30 seconds to hit the ground. The height of the cliff can be calculated using the equation h = v_0 t + (1/2)gt^2, with an initial velocity (v_0) of 0 and g as the acceleration due to gravity. The discussion emphasizes that this type of question is more appropriate for the homework section of the forum. Participants are directed to continue their discussion in the designated area. The thread has been closed to maintain organization.
#1
thschica
47
0
A stone is dropped from the top of a cliff. It is seen to hit the ground below after 3.30 s. How high is the cliff?
Imagine a charged sphere at the origin connected through an open switch to a vertical grounded wire.
We wish to find an expression for the horizontal component of the electric field at a distance ##\mathbf{r}## from the sphere as it discharges.
By using the Lorenz gauge condition:
$$\nabla \cdot \mathbf{A} + \frac{1}{c^2}\frac{\partial \phi}{\partial t}=0\tag{1}$$
we find the following retarded solutions to the Maxwell equations
If we assume that...
Maxwell’s equations imply the following wave equation for the electric field
$$\nabla^2\mathbf{E}-\frac{1}{c^2}\frac{\partial^2\mathbf{E}}{\partial t^2}
= \frac{1}{\varepsilon_0}\nabla\rho+\mu_0\frac{\partial\mathbf J}{\partial t}.\tag{1}$$
I wonder if eqn.##(1)## can be split into the following transverse part
$$\nabla^2\mathbf{E}_T-\frac{1}{c^2}\frac{\partial^2\mathbf{E}_T}{\partial t^2}
= \mu_0\frac{\partial\mathbf{J}_T}{\partial t}\tag{2}$$
and longitudinal part...
Is it true that in any mechanical set-up, it is possible to predict the nature of Normal Reaction ( magnitude, direction, etc. ) without solving through the dynamical equations of motion and constraints for the set-up as Normal Reaction is completely unknown? I mean is it true that we can explain NR intuitively beforehand?