How to choose Gaussian surface
1 Why do we choose a spherical surface as gaussian surface for a point charge to calculate electric field? In my view, the reason may be i. If we take the point charge at centre, each point of...
View ArticleIs Mechanics applicable in Space?
Please explain the term "mechanics and space" and then explain if Mechanics is applicable in Space. My friend says that since there is no atmosphere and gravitation,Mechanics cannot be applied...
View ArticleVelocity of air coming out of a nozzle
Hello, first time poster here! :smile: I need to find the speed of air directly coming out of a nozzle connected to a compressed air tank. Inside the tank I have 30 psi gauge pressure (~207 kPa) and...
View ArticleWhy only 2 sig. fig.?
I have the following info for a question: x0 = 380m a = -9.80m/s^2 t = ? v0 = 0 I use the formula x = x0 +v0t + (1/2)at^2 When I solve for 't' I get 8.80631 I figure I would round to 3 sig. figs. and...
View ArticleGriffiths Chapter 10 del cross position vector
I am working through chapter 10 of Griffiths electrodynamics (for fun and in my spare time). While I dont have a formal bucket list, getting to an understanding of how Newtons third law is not as...
View Articlemomentum conservation law: Head on elastic collision
Hi guys, I've been thinking on a problem for a while which really bothers me. I've been trying to mathematically solve the following problem: A train approaches the station at a velocity of V=50 m/s....
View ArticleUnanswered questions in Classical Mechanics?
Are there any unanswered questions in classical mechanics? By unanswered I mean unanswered and attempted. I could easily think of a question which has never been asked. Edit: Sorry about the misspelled...
View ArticleBest book for Classical Mechanics for Undergrad Student
I was just wondering, what book would you suggest for me as a undergrad student going into 1st year at university. I will be completing an honours in math and physics, and I just want some material to...
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rotation induced by moving center of mass
Two identical uniform beams are connected together by a set of servo motors. When the motors activate the two beams will come together uniformly and the center of mass of the system will move outward...
View Articleusing Kirchhoff's rule in RC circuit while charging
Hello I have a conceptual question about using Kirchhoff's voltage rule to derive expression of the charge in the RC series circuit when it is being charged by certain EMF. Usually most books start by...
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Differential pressures balancing a valve armature
I have 2 questions on a two-port valve that I would like to ask for assistance with. There are three pairs of drawings below that need explanations: The first pair shows a one-piece armature with two...
View ArticleWhy is there a limit to power supply?
As stated: every now and then you see maximum power output to a motor, a turbine, but why is there a limit to the power output to these electrical/mechanical devices? isn't Power just equals to F*v for...
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Why does perspective skew some lines and not others?
Imagine looking at a set of x-y-z axes, from directly along the z-axis. Say in this image, the road is the line z=0. Why is it, that only lines on or parallel to the z-axis get skewed? All the surfaces...
View ArticleHeat flow through 2 conductors
Say I have a metal object and a wooden object at 0 degrees and I touch them. The metal object would feel colder because it is a better conductor of heat and so it removes heat away more quickly. Would...
View Articleuniformly charged ring
hi every one on an exercise on book we ask us to find the electrical field for a uniformly charged ring where we gonna find : E=kqz/(z2+R2)3/2 then we have to derivate it wth respect to z and we find :...
View ArticleRocket with higher velocity than its own thruster.
If I'm traveling at 22000 miles per second and fire a thruster with an exhaust velocity of 1700 miles per second does the thrust creat drag because I'm going faster? If not what is the effect?
View ArticlePotential energy of water from electrolysis
Could I please have help with something: If I generated hydrogen via electrolysis from water, sent it high up a long tube then converted it back to water (via a cell or motor to reclaim energy) then,...
View ArticleHows sound generated?
When a metal ball rolls on a metal surface, we can hear some noise. But when the metal ball rolls on a cloth, we cannot hear anything. Why is that? This question has bothered me a lot...
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Vector addition confusion
I am stuck on this one: According to me, the only correct answers are [itex]\vec{r} = \vec{t} - \vec{s} \\ \vec{r} + \vec{s} = \vec{t}[/itex] But according to the key, these are also correct...
View ArticleElectric Field and Circuits
I was reading my physics textbook which says that a current carrying wire has no net charge and thus no electric field because the electrons cancel the protons in the atoms of the wire. Would there not...
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