Laws Definition and 1000 Threads

Homework Statement A 2.0kg physics book is dropped from the roof of a skyscraper 240.1 m high. While the book is falling to the ground, a horizontal wind exerts a constant force of 11 N on it. Ignore air resistance. a. How far from the building is the book when it hits the ground? b. How...

Hi, I am taking a high school physics course, and there are a few points at which I am getting a bit of confusion. My first area of confusion relates to Newton's Laws. There are a few scenarios in which I am not clear as to the interaction of forces, etc. a) Exactly why does putting...

Homework Statement its 3.8 x 10^8 from Earth's core to the lunar's core calculate the gravitational attraction exerted by Earth on the moon Homework Equations ag = GM/ r^2 G= 6.67 x 10^-11 M of earth= 5.98 x 10^24 ... r= 6.37 x 10^6 M of moon= 7.36 x 10^22 ... r= 1.74 X...

how do i calculate potential differences around the loops is i3+i4 equal to i5?? this is actually from maths and i completely forgot how to do calculation around electrical circuits from physics could anyone please help me!

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Hi All, Concerning the first circuit in the attached figure: By applying Kirchhoff laws we arrive at two different currents in the central resistor. But if we consider the second circuit with its auxiliar resistances we see no problem with the definition of the central current. Is it due...

Hi. When trying to derive the equation for voltage across a discharging capacitor in series with a resistor using Kirchhoff's laws, I got stuck. My attempt was that the voltage gain across the capacitor should equal the voltage drop across the resistor, therefore q(t)/C = i(t)*R, or q(t) -...

I'm sorry I didn't use the outline provided automatically by the thread. My question does not focus on the maths; sorry if I chose the wrong section (I'm new here). Anyhow, what I'm asking is: Why does Newtonian Physics state that a moving object with uniform velocity (abiding by the...

The ideal gas has the following requirements. 1) there are no intermolecular forces between the molecules. 2) the volume of the gas is negligible compared to the volume of the container they occupy. 3) the interactions between the particles and the container is perfectly elastic (total kinetic...

Do all electric motor's follow Faraday's law and Lorentz? Is it safe to say generalize that statement?

I think that it is relatively easy to simply count the number of physics that are aware for us as of February 2014. Probably there is statistics that deals with it and can tell us how many laws of physics exist now; maybe this number is equal to 1000, maybe more, I am not aware of it. But...

Homework Statement A 4.0 kg toboggan rests on a frictionless icy surface, and a 2.0 kg block rests on top of the toboggan. The coefficient of static friction μs between the block and the surface of the toboggan is 0.58, whereas the kinetic friction coefficient is 0.48. The block is pulled by...

Homework Statement Using Ohm's and Kirchoff's Rules find the unknown resistance Rx Homework Equations V = IR Sum of currents at a node is zero Sum of voltages around a loop is zero The Attempt at a Solution For the 2 ohm resistor I found the voltage to be 4V by the formula...

Homework Statement Homework Equations \sum I_{in} = \sum I_{out} \sum \epsilon = \sum pd The Attempt at a Solution Can anyone identify any mistakes in these? Probably signs I = I_1 + I_2 12=4I_1 +3I 5=4I_1 - 2I_2 12-5=2I_2+3I

When I had a school tour to A water park, there I observed that when a heavy boy used to slide down a water slide(and stop at β), he used to go further than where the ligher boy used to stop after sliding(α). But the friction will act more on Heavier then why is he going further?

Hi, Assume we have a source that emits several copies of the same quantum state which is a superposition of several eigenstates of the Hamilton operator with different energies. We can calculate the expectation value of the energy of this state and therefore also the energy the source...

Homework Statement In the arrangement shown, all surfaces are frictionless, mass of block M = 30 kg and m = 20 kg. If F = 180 N , Find accelerations of both the blocks 2. Doubt How much force will be applied on the larger block M by the pulley(coz of tension)? 1. T towards right 2. T towards...

Im planning to build a robot and wondering if laws of physics are present!

Homework Statement Two blocks of mass m1 and m2 (m2 = 2 kg ; m1 = 3 kg)are connected with a spring moving on smooth plane. The acceleration of block of mass m2 is 2 ms-2, find acceleration of block with mass of 3kg. 2. The attempt at a solution Let external force of F be applied on Block...

Homework Statement In the arrangement shown, all surfaces are frictionless, mass of block M = 30 kg and m = 20 kg. If F = 180 N , Find accelerations of both the blocks 2. Doubt What amt of force will act on larger block M, just T(coz of horizontal string around the pulley) or...

I was arguing today with a friend and the argument seemed pretty pointless because we had nothing to back up our facts with, so I thought about hearing your opinion(s). Do black holes violate laws such as the conservation of matter + conservation of energy? I'm currently leaning towards 'yes'...

Hi I am stuck with a question which I have attached a photo of, it is one involving friction! I have done a few of these questions already and find it is when I am defining forces etc it's where I go wrong, not the easy computational part:( I also have attached my attempt at the solution and...

Homework Statement I have been given a small task. There is two parts. (I have translated it from another language): "Santa is flying in his sleigh 836,6 feet (250 meters) above the ground. To save time, he will let the packets fall from the sack down the chimney of a house. The package is...

Homework Statement A block of mass 2.20 kg is accelerated across a rough surface by a light cord passing over a small pulley as shown in figure.The tension T in the cord is maintained at 10.0N,and the pulley is 0.100m above the top of the block.The coefficient of kinetic friction is 0.400m...

Homework Statement A car accelerates down a hill,going form rest to 30.0m/s in 6.00s.A toy inside the car hangs by a string form he car's ceiling.The ball in the figure represents the toy,of mass 0.100 kg.The acceleration id such that the string remains perpendicular to the ceiling.Determine...

The laws of motion -- rock sliding on a roof Homework Statement One side if the roof of a house slopes up at 37.0°.A roofer kicks a round,flat rock that has been thrown onto the roof by a neighborhood child.The rock slides straight up the incline with an initial speed of 15ms-1.The...

The photo shows below is my attempted solution. Is there any mistake so I cannot get the correct answer?

Although scientists once thought that radioactivity violated the law of conservation of energy, then new understanding of nuclear decay helped demonstrate that the law was fact. So why do we continue to call the Conservation of Energy a law, and not a fact. Why not a principle? Is there a...

Does the law of the conservation of energy apply to the light in our universe? If yes, is our universe a closed system? If no, is our universe losing energy?

I've looked alittle at the gas laws and I get the feeling that they are simplified. From what I can see they don't take intermolecular forces into account. Will the intermolecular forces simply disappear or just get so weak that we don't take them into account? The gas law I'm thinking about...

I have access to a remote controlled submersible and I want to use it to do some physics with some students of mine. We are examining Newton's Laws. I intend to use spring scales to determine the mass of the sub and the max force the sub can exert by applying full forward thrust while reading a...

PROBLEM- http://ijso2013.hbcse.tifr.res.in/files/qna/theory-2008.pdf questions 1-10 to 1-12. ATTEMPT AT SOLUTION In the first question, I am unable to understand how the current in AB is equal to 0.2A when the resistance of AB is 0(galvanometer is ideal). As current is equal to V/R, it would...

When doing FP1 ages ago I discovered a way to seemingly get i3=±i, and since then nobody has provided a proper explanation for why the positive solution is impossible. Standard solution i3=i2.i =-1.i =-i 'flawed' solution i3=(√-1)3 =√(-1)3 Using the laws of surds, √a.√b=√ab =±√-1...

Hello, I am taking intro Physics and we are having a little quiz this friday. Professor gave us handouts and told us to solve them by ourselves, and then study those problems because the same problems will be on the quiz. Now, my problem is, is that I really don't understand the subject...

Can the laws of physics work with any number of dimensions (whether they be space or time)? That's what Lisa Randall claims, but am seeking clarity. If so, does that mean Quantum Mechanics will still predict the same results in 5 or 6 dimensional universes, and the equations will stay the...

following is what little I know about energy:Energy: its the ability to do the work. First law says you cannot create nor destroy energy but can transform it to from one form to another. so its always 100 % conversation. but in a process you have 'work' done also. so does that mean 'work'...

Ideal gas laws question.. Help! Homework Statement Volume of 150cm^3 of an ideal gas has an initial temp. Of 20 degrees celcius and an initial pressure of 1 atm. What is the final pressure if the volume is reduced to 100cm^3 and the temp is raised to 40 degrees celcius. Homework...

I attached an image of the problem I am currently working on. I am having a hard time understanding when to use cosine or sine when referring to the sum of the forces in the y direction or x direction. I have a general understanding as to where you initially place your coordinate system. If you...

Homework Statement Two forces are acting on a 0.250-kg hockey puck as it slides along the ice. The first force has a magnitude of 0.405 N and points 25.0° north of east. The second force has a magnitude of 0.565 N and points 75.0° north of east. If these are the only two forces acting on the...

Homework Statement An ideal gas has the following initial conditions: Vi = 520 cm3, Pi = 3 atm, and Ti = 100°C. What is its final temperature if the pressure is reduced to 1 atm and the volume expands to 1000 cm3? Homework Equations I used the equation p1 x v1 / t1 = p2 x v2 / t2...

Homework Statement A book is sitting on a table, which is sitting on the Earth. The book has a weight of 10 N and the table has a weight of 20 N as labeled on the diagram. a. Find all contact forces, F12. (For example, “FEB” would mean “Force of Earth ON Book”) b. Next to each, tell me...

Homework Statement Just started tension problems and having some trouble figuring out how to approach the problem. Thanks for any help in advance. Consider a rocket that is taking off and towing a large container of trash. The rocket’s engines exert a force, F, that causes the rocket and...

What do textbooks mean when the gas laws are "combined" to make the ideal gas law? I think that if the equations were combined, the result would look something like this: P = k(T)T P = k(V)/V P = k(n)n P^3 = (k(T)T * k(V)*k(n)n)/V or P/T = k(T) PV = k(V) P/n =...

Hi, In classical induction machine analysis, the induced voltage (or curl of the electric field) is equal to the time rate of change of the magnetic field (B) plus the 'speed voltage'. This is understood very easily from electrical circuit models of the machine. However, going purely from...

Homework Statement A 1200 kg car travels at 50 km/h and experiences air resistance of 5000 N and road friction of 2200 N. If the wheels push with a force of 7500 N, what is the car's acceleration? Homework Equations a = ƩF/m The Attempt at a Solution I got ƩF = 8590 N [E52°S]...

I am having a very hard time understanding these two problems I have attached. I have read the chapter in our text over and over again, but do not see the correlation or how to exactly set the problems up. I recently had surgery on my writing hand and missed a large portion of this class, so I...

simple i know but i have just hit a blank. a projectile of mass 250g traveling at 1200m/s impacts and sticks to a stationary 3500g object. What will be the resulting velocity of the two combined objects... Many thanks

Homework Statement A 0.075-kg arrow hits the target at 21 m/s and penetrates 3.8cm before stopping. (a) What average force did the target exert on the arrow? (b) What average force did the arrow exert on the target? (c) An identical arrow strikes the target at 42m/s. If the target exerts the...

Source of Question J.N. Reddy states in Finite Element Method: "Variational forms of the laws of continuum physics may be the only natural and rigorously correct way to think of them. While all sufficiently smooth fields lead to meaningful variational forms, the converse is not true: There...

Homework Statement Find i_1,i_2,v_A,\text{ and }v_H in the ladder network. Calculate the power dissipated in the 2\;\Omega resistor. http://i.snag.gy/PIhxl.jpg Homework Equations Kirchhoff's Laws (i.e. current law, voltage law). The Attempt at a Solution Ok, I know that I...