Recent content by Nytik

Technically not an introductory physics course, this is just a question from the "Exercises for the Feynman Lectures on Physics". The question doesn't really fit any other forum though as far as I can tell. Thanks for your help everyone, I should be able to reach a solution from here.

Hi, I don't quite understand that. First I should note there are no velocities involved here, we are considering two static states in one of which A is 1m further down than in the diagram. But for this to be the case, more than 1m of string should come over the pulley as the string is at an...

Homework Statement The system shown in Fig. 2-6 is in static equilibrium. Use the principle of virtual work to find the weights A and B. Neglect the weight of the strings and the friction in the pulleys. Homework Equations Conservation of gravitational potential energy. The Attempt at a...

Depends on the context. The wavenumber of a wave has units of m^-1; that is, the number of wavelengths per unit distance.

Looks good to me. If that isn't working then double-check where you got the gallon-litre conversion; I know that a US gallon is different to a UK gallon and I don't know which countries use MasteringPhysics either!

Not quite, remember it's ft^2 and m^2 so you have to do that conversion twice.

Sorry, I think I ninja-edited while you were quoting (perhaps). Read it now and it should be fine.

You do subtract them; everything you have done up to this point is correct.

You have units of ft^2/gallon and you need to convert to m^2/L. You have already done the ft to m conversion, now you need to do gallons to litres.

Exactly that.

Yeah, he's saying it's wrong to just add the components. Consider the vector and it's components as a triangle (I assume you're familiar with this representation). You're trying to the find the length of the hypotenuse.

Sorry it's taken me so long to get back to this thread. Did you check those numbers with the equations (sub them back into make sure they work)? Because they don't look correct to me. By the way, when solving the two equations the preferred method is to keep all symbols in until the final...

Hopefully you read this before solving, I accidentally missed out a 1/2 in the momentum equation (which I have now edited in). Sorry about that!

That equation is perfect, I'm just going to add some subscript to make things clearer: \frac{1}{2}Mv_{i}^{2} = \frac{1}{2}Mv^{2}_{1} + \frac{1}{4}Mv^{2}_{2} So v_{1} is the resulting velocity of the big block, and v_{2} for the small block. Also notice I have substituted in the mass of the...

The momentum of the big block before they collide must be equal to the combined momentums of the big and little block after the collision. Do you know how to write an equation for this? Similarly, the KE of the big block before the collision equals the combined KE of the big block and little...