Recent content by kuruman

As you have discovered, ChatGPT doesn't give a hoot whether you learn or not because it is constitutionally incapable of diagnosing where you went wrong and why. Here is my diagnosis. It looks like your mistake is in not having in your head a clear picture of what the "system" is in this case...

What about us at Physics Forums? The ChatGPT solution matches mine. I recommend that you read this article which includes a step-by-step method for solving variable mass problems. Start with equation (2).

To @Su6had1p : I have a solution under certain assumptions. Please post the answer that you are told is correct to compare. Note that the problem is asking you to find the velocity as a function of time. Your solution has no explicit time dependence on the right-hand side.

The minimum mass may have something with another part of the problem, e.g (b) Find the minimum value of the second mass so that the time of flight after the collision is ##t_2## seconds if the masses stick together (or some such thing.)

That's another way of looking at it.

The expressions for the magnitudes are obtained from ##|\mathbf a + \mathbf b|^2=(\mathbf a + \mathbf b)\cdot(\mathbf a + \mathbf b)=a^2+b^2+2ab\cos\alpha## ##|\mathbf a - \mathbf b|^2=(\mathbf a - \mathbf b)\cdot(\mathbf a - \mathbf b)=a^2+b^2-2ab\cos\alpha## where ##\alpha## is the angle...

The collision time happens once and cannot be double-valued. You can make your life simpler and avoid quadratics if you consider the velocities. 1. Write expressions for the velocity of each can as a function of time. 2. How is the velocity of the first can v1 related to the velocity of the...

Cancelling out where? Do you see what you need to do to find the electric field, magnitude and direction, for all values of ##z##?

It appears to be more complicated than that. I had a PM exchange with Greg and he observed that it might be the inclusion of LaTeX in an ordered list that messes up the rendering. An additional complication is that this appears to happen with posts on regular threads but not PM messages where...

For some reason the LaTeX works in "Preview" mode only. Here it is Answer the following four questions and you will see why the electric field is zero at z = 0. In what direction does the electric field point in region 2, to the left of the distribution? In what direction does the electric...

There are three regions of space: Inside the distribution ##~-\frac{a}{2} \leq z \leq\frac{a}{2}## To the left of the distribution: ##~z\leq-\frac{a}{2}## To the right of the distribution: ##~z\geq\frac{a}{2}##. You need to find the electric field in each region. This means writing the...

Q is what you are looking for. What is C for a concentric shell capacitor in which the outer shell has infinite radius?

Where did the equations that you posted come from? Are they supposed to be the solution to the problem you posted or some other problem? I am particularly suspicious of this What is ##\rho## in the region ##r\leq a## when there is vacuum in that region? Answer: Zero. In any case, if the...

That was my interpretation when I posted #11.

To @EricaC: It occurred to e that you might wish to explore the use of smartphones in physics experiments. Not all schools have photogates and thermistors but it's a safe bet that a great number of students have smartphones who will love the excuse for bringing them to school. See here...