Recent content by sigma

Yeah. Not sure if i got this in the right section. Thought I was posting in the general physics forum? -Sigma

Greetings nerds! Please just read the bold-style basic question at the end of the message if you don't care what my personal problems are. You'll find out soon enough... when I have summoned founds for my 0.27 billion rockets engines. I have this problem: My "biological clock", the part of...

Hi. Got this quite interesting problem: A projectile is launched at some velocity at an angle a over a plane inclined at an angle b. 1. How far, measured along the incline, will the projectile fly? 2. What angle a will give the longest distance? Any suggestions/hints on possible...

Ok. I see. I've done some research and found that I can use this expression: p + rho * g * h + 1/2 rho * v^2 = constant at any point in the water. p: pressure rho: water density h: water height v: flow velocity I understand this is some variant of Bernoullis' law, or a statement of...

Really? Can't I assume that the thrust from the motor is the pressuere in the tank multiplied by the nozzle area, and then add a correction factor for friction/turbulence loss. Then calculate mass flow from this. How do i know what pressure I need to design the tank for? How do I know how...

Heya. Let's say I want to build a water rocket and I want to pressurise it with a 12 or 16 g CO2 canister used for powering airguns. I want to calculate the optimal size of the pressure tank, and I want to predict the thrust of this device at various nozzle diameters. So here's the...

Hi! I've written a simple software to calculate projectile trajectories when air resistane can't be neglected. I'm planning to test the software with a light ball and a cannon. My model simply say F = -k * A * v^2 The force of drag F is proportional to the velocity v squared. k and A are...

Do you accelerate faster if you hold on to the train with both your hands instead of just one hand? No.

Sounds tricky?

I'd consider the retardation to be along the direction of the bullets' motion. It's an iteresting problem, still I think there's to little information to say anything more precise than ~1500 m/s

I'd consider the velocity of the bullet to be 1500 m/s. 0,2 m is way to short a distance for any signifficant change in velocity given a retardation of only 3,08 m/s^2. Just don't you go do anything stupid..

Well I read about wave interference in microwave owens on a webpage and found the marshmallow thingo some place else. The precision of it was way better than expected, or perhaps we were just lucky?

Aww. So soon. Okay you were right. Congrats! We were lucky because the wavelength was almost precisly half the distance between the walls, I assume this made the resultant wave more articulated. We also noticed that the marshmallows got hot in a sort of "checkboard pattern". This led us to...

That's the spirit of it!

Hi! See if you can answer this: Yesterday me and my friend measured the frequency of a microwave owen. Our experiment indicated 2300 MHz while the "right" answer, found on a sign on the back of the apparatus, showed 2450 Mhz. Our error hence: ~6%. I find this pretty impressive, as I hope...