Confused — 400 discussions

I am extremely confused in Acceleration and velocity please explain in detail with example

I was given this info r=1.5 m d=3 m F= 50 N angle= 110 degrees 1. What torque is applied? T=Fsin T= (1.5)(50)sin(110) T=70 J 2. At what angle would enough force be applied to achieve maximum toque? T=Fsin T= (1.5)(50)sin(90) T=75 (joules) 3. If someone continues to push with a force of 50 N...

Homework Statement Verify (https://ucdsb.elearningontario.ca/content/enforced/4850117-BL_1415Sem2__MAT_MCV4UU-948314_1_ELO/MCV4UPU01/MCV4UPU01A06/images/vec-a.gif?_&d2lSessionVal=Y3hirJUTSYjH76OEZwqHIBATE&ou=4850117 +...

Hii greg i am akash I want to know how people in a forum are so advance . I also be like them . So can u help me. I want to know how u and other people get knowledge of everything. Plzz help me. I want to know your secret how u solve the problems

Homework Statement My teacher introduced the third dimension (## R^3 ##) and higher dimensions to my class using vectors. Later on, my teacher introduced functions of two or more variables and now there's no mention of vectors. I am confused as to how vectors (i + j + k) and functions of two...

I am making mess of the following expression.. i have following expression ## \frac{\partial{g}}{\partial{g_{\mu j}}} *g_{\nu j}=g \delta^{\mu} _{\nu} ## then I have sum over j only in the above expression. But above expression is nonzero only when ##{\mu}## is equal to ##\nu##. So we have ##...

Homework Statement http://puu.sh/fYQQj/12819720c6.png My question is in the attempt at the solution (Number 3) 2. Homework Equations The Attempt at a Solution I know how to get to lim t→∞ 1/(1-p) * (t^(1-p) - 1^(1-p)), I'm not sure what to do to get the 1 instead of 1^(1-p) in the above image

when we are talking about a linear transformation the argument of the function is a coordinate vector...is this true? another question...when i see a column vector...these are the coordinates of the vector with respect of a basis...is this true? for example if i see... (({{1},{3}}))^T with...

Homework Statement 1. Find a formula for (f g)(x) = ? 2. Find a formula for (f f )(x) = ? 3. Find a formula for the composition below. g(h(x)) = 4. Find a formula for the composition below. (h g)(x) =The Attempt at a Solution 1. f(g(x)) 2. f(f(x)) 3. (g º h)(x) 4. h(g(x)) Why are these...

The reason why the work energy theorem " ΣW = Δ KE " only includes kinetic and not potential energy, is because gravity undoes the potential energy ? What I mean by "undoes" here is, If you were to, for e.g., lift an apple up a vertical distance, but also accelerate it while lifting it. Then...

Homework Statement The problem I have is not actually so much a physics problem but more of a logical problem. When we look at rulers and any kind of measuring tools, we start from zero. We count the number of intervals instead of the divisions. Suppose we have a video with 7 frames per...

Type Ia Supernova are generally thought to be white dwarfs that, either by accretion of mass from a companion (single degenerate), or as a result of a merger with a white dwarf companion (double degenerate), approach and then exceed 99% of the Chandrasekhar limit of about 1.44 M☉, at which point...

When the observer B is traveling at a very high speed, the observer A on the ground will record a time dilation. But at the same time,from the point of view of B, A is also traveling at a very high speed relative to B. Here comes the question:does that mean they both record the time...

Hi, I am confused over the potential energy equation. I have been taught that potential energy is MGH M=mass, G=gravity on surface, and H=height from earth. However being on the internet and learning more i have noticed people use GmM/r^2 and i am very confused why it is switched. please help me...

I am from New York, and a physics student. ( not trying to give to much info on the internet.) but i was curious in why people on the internet use PE equation as GmM/r^2 when i was taught that it was PE=MGH? please help me with me confusion? thank you.

The equation for kinetic energy is: k = 1/2*m*v2 This confuses me because this indicates it take more and more energy to accelerate... Lets imagine a rocket in space (assume the mass of the rocket stays the same when accelerating) - the formula suggests it would take more energy (therefore...

I was thinking about the motion of two stars in a binary star system, but there is something I cannot quite figure out. Suppose you have a binary star system with two stars masses m1 and m2 with m2>m1 so that m2 is closer to the centre of mass of the system. Then when the two stars are as far...

I am teaching myself thermodynamics (and really enjoying it!) but am slightly confused about Carnot's engine. From the equation efficiency=1-T(cold reservoir)/T(hot reservoir), I see that the most efficient engine is one where the difference in temperature between the cold and hot reservoirs is...

1. In Griffiths, in the section where he discusses the 'total' spin of two spin 1/2 particles (''Addition of angular momenta'') he starts of using a notation new to me. Namely ##\chi=\chi_1\chi_2## where I know what ##\chi_1## and ##\chi_2## represent independently, which has been discussed in...

I would really appreciate it if people could help with these integrals. We are supposed to be doing integrals with this table here: http://math.boisestate.edu/~wright/courses/m333/IntegralTablesStewart.pdf Here are the two integrals. Technically, I only need one of them completed...

Is there an f(x) which is differentiable n times in a closed interval and (n+1) times in an open interval? I think I saw this in a paper related to Taylor's theorem (could be something else though). It didn't make sense to me, how can something be differentiable more in an interval that contains...

Let's say that block A is suspended vertically by a massless rope which you are holding and block B is suspended under block A by another massless rope. If I am drawing a free body diagram for block A, would the downward force be the weight of block B and Tension as well as an upward Tension...

I read in a magazine (namely Scientific American) that the Standard Model successfully combines Quantum Mechanics with General Relativity, but I also remember reading in The Elegant Universe that the Standard Model fails to do so. What's true and what's not?

Homework Statement A cylinder with two rods coming out of it. The ends of the rods are fixed. A force is applied through the center of the top surface of the cylinder. What are the reaction forces and moments at the rod ends? Here is a diagram of the scenario: http://www.imgur.com/Tsdhmzf.jpg...

Hey, i was doing a multiple choice question and i got 0.83/1 on it... There were 6 options to choose from and you could choose as many as you liked. I only picked one of the options. I'm confused as to how or what equation is used to calculate what mark you will get on each multiple choice...

I learned that integrals are finding the area under a curve. But I seem to be a little confused. Area under the curve of the derivative of the function? Or area under the curve of the original function? If an integral is the area under a curve, why do we even have to find the anti derivative...

Hello, I am preparing for the IIT JEE exam, The toughest entrance exam in the Indian subcontinent, and i am struck in confusion about the theory regarding waves in Physics. The problem is that I can;t visualize the sine-cos functions physically , as I could visualize the movement of pulley...

Homework Statement An inclined plane is used to raise a 100 kg box to a height of 5 m. How long must the inclined plane be if a force of 250 N is used to push the box up the inclined plane? Homework Equations i have search and searched all over google to try to figure this out.. I am not...

Hi, does anyone know how to integrate e^-x (sin(nπx))? I have tried part integration but that goes on until infinity... and I am not sure how to use the substitution method...Please help! I have tried taking e^-x as U but then I end up getting the entire canceled off then...

O.k. I am seriously confused... Not being to good at math but nevertheless interested in set theory, infinity, etc. I started reading Mary Tiles, The Philosophy of Set Theory (Dover edition). I particularly wanted to know more about the relation between infinite ordinals and cardinality, but...

So, I'm currently writing a mathematical analysis of a bullet with a muzzle velocity of 790 m/s. I have found that the standard equation for drag force... Fd = 1/2 * ρ * v2 * Cd * A does not work because the drag coefficient for a bullet (.295) does not account for supersonic speeds. What I...

I want to become a theoretical physicist. I was wondering the LEVEL of maths i will need to do. For example i downloaded a book for sets "INTRODUCTION TO SET THEORY" BY HRBACEK, JECH. It has got a lot about sets. But when i look into another book it has limited concepts. So i don't have any idea...

Homework Statement...

I'm new here, and I have a question that might be easy but really confuses me. Does the volumetric flow rate of incompressible fluid change across a valve?. Based on my analysis, no it can not change since the mass is conserved, and since it's incompressible fluid. I know that the velocity will...

Supposing a man named Bob falls into a black hole, an instant of Bob's perceived time would be a nearly infinite amount of time to the rest of the universe due to relativity and the effects it has in and near black holes. Okay sure, but we also know (to my knowledge) that black holes "evaporate"...

So I have been roaming topics in this forum for days now... Short story (past): I enjoyed science ever since I was young. It was always my favorite even if it was not my best subject. I went through phases where I wanted to be a volcanologist, a paleontologist, a doctor, a biologist, chemist...

to skip the introductory part go straight to the question between the hyphens. I wanted some help mending two seemingly contradictory concepts. on one hand we have ohm's law: I= \frac{V}{Z} stating that current is proportional to the potential between two points. makes sense. on the other...

So i know how to work out moments sort of but i am confused on what i am actually working out. So i get the answer in Newtons a Metre, but what does that mean exactly? And why is it that when i divide the other side of a levers length by this it gives me the force on the other side?

Recently I started with multivariable calculus; where I have seen concepts like multivariable function, partial derivative, and so on. A week ago we saw the following concept: directional derivative. Ok, I know the math behind this as well as the way to compute the directional derivative through...

An example: A car that senses if you have your seat belt on and the door is closed I can declare: D - for door S - for seat belt D is 1 is door is open, 0 if door is closed S is 1 if seat belt is on, 0 if it's off This is all very straight forward and can be implemented with combinational...

Hi, I am trying to solve one problem of circular motion and I searched on Internet and found many things and I am confused about different forces or I think same force is shown as different symbol. What I learned is as follows:Force = F = ma (horizontal movement - where height is not involved)...

Hey! :o At the end of a program I have to delete all the data structures and to free all the allocated memory. What am I supposed to do?? (Wondering)

Is the use of proper time just for ease of simple equations? ie you could define velocity and acceleration with any reference time you want but all other choices are arbitrary other than proper time- proper time is the only time that is special. It seems to me that if you use proper time then...

Hello, everyone. To give you some context, let me give you some background about myself. I apologize if this is overly sentimental but I can't help it. As a child, I was fairly bright and very intellectually curious. I got good grades. I was always among the top two in my class. I loved...

In my textbook, it says that pV=C (Boyle's Law), V/T=C (Charle's Law) and that P/T=C (pressure Law). The problem is that I cannot see how the first two equations combine to give the last one. If I divide the first equation by the second, I get that pT=C, which certainly is not the same as the...

So I am kind of confused about the role of force when calculating work. Specifically, when defining work using a line integral. There is a paragraph in my calculus book that is really throwing me off and its really bugging me so much I can't continue reading unless I fully understand what's...

Hello, I am confused about a problem regarding work done and pulleys. I am confused mainly by the last two, but not 100% confident in the first two either. 1. Homework Statement Two blocks are connected by a very light string passing over a massless and frictionless pulley (Figure 2). The...

I am a applied physics major with an emphasis in physical electronics (so basically I take a lot of solid state physics classes with my other normal physics classes), and I go accepted into a program where I start taking graduate classes during my last year of my bachelors (current year) and...

Hi everyone. I am starting to study transisors at Uni. and I am confuse in some main concepts. i thought about posting it here so someone can help me up. are pi hybrid signals equivalent circuits used with the same porposes as small signals equivalent circuits? or are pi hybrid signals, small...

The high school textbook I’m reading says this: Statement A “Many household appliances contain an electrically heated resistor. A resistor is a device that opposes the flow of current and as it does this, heat energy is produced. E.g. electric kettles, electric fires, light bulbs. If we...