Conceptual Definition and 874 Threads

Homework Statement The Mass of an object doesn't affect the angle at which a curve must be banked. The law of inertia, however, states that the motion of any object is affected by its inertia, w/c depends on its mass. How can objects rounding banked curves obey the law of inertia if the...

Homework Statement Two springs are connected, one is a heavy spring and the other is a light spring. A pulse is traveling down spring A, towards a junction with spring B. Which of the following statements are correct/incorrect. A. If spring A is the heavy spring then the transmitted pulse...

Homework Statement A spaceship is travels in a straight line (to the left) past a space station that is at rest. the spaceship is speeding up relative to the space station. inside the ship, there is a block attached to the end of a light spring. the spring is extended by a fixed amount, as...

Homework Statement 1. Do you use the equation of continuity and Bernoulli's equation simultaneously in a question? When do you use them? 2. In simple harmonic motion, why is the velocity shifted to left of the displacement by pi/4? Homework Equations pressure + .5density x velocity...

Homework Statement Here are a couple of conceptual questions from my cumulative review. 1. Is energy released or absorbed when a gas changes to a liquid? 2. If a yo-yo is being whirled around by its string in a vertical circle, does the string apply an outward force or an inward force...

Please tell me if I am understanding this correctly, or please point out where I am going wrong... imagine you have an open ended u-shaped tube filled with water. The pressure on left side of the U is the same as pressure at right side, because they are both open to atmospheric pressure...

Switching to a Matrix Hamiltonian -- Conceptual Issues It's probably very clear and well-established for those who rigorously studied Quantum Mechanics but I don't think what I am going to ask is easily 'google'-able but if it is so - please send me to the correct source before spending time...

Why is air pressure always factored in when calculating pressure at a given depth of water? Why is the force from air pushing down on the surface of water the same at 1m as it is at 100m? there is no air underwater, so why do we still need this value when doing pressure-depth calculations?

I have done these questions but I am trying to figure out if I did them the correct way. I cannot find an answer key yo check them by. Does anyone know the answers? http://cosmos.bgsu.edu/communities/research_community/MeasurementInst/pdfs/Motioneval.pdf

Homework Statement Explain why a tile floor feels cold on your feet, but a carpeted floor in a room with the same temperature feels warm. Homework Equations N/A The Attempt at a Solution I think it's because the carpet is a better insulator and loses its energy much more slowly...

Homework Statement The three thin rods shown below are initially at the same angle, with one rod twice as long as each of the others two. Rod X is made of brass (density = 8.6 g/cm3), the others are made of aluminum (density = 2.7 g/cm3). All rods are released from rest at the same time...

Homework Statement Tell whether each of the following forces are conservative or non-conservative. a) the force applied by the club to a golf ball during a tee shot b) the force of gravity on the ball during flight c) the drag force by the air on the ball during flight attempt...

Homework Statement I don't quite understand how to read circuit diagrams, so I'm not sure how to find the equivalent resistance in some cases. What is the equivalent resistance of circuits A and B? I drew a picture to help me explain what I'm talking about: Homework Equations...

1. Why is it that when you swing a ball around your head, the string or rope attached to the ball is always tilted down a little? That is, the rope isn't parallel to the floor, it is at a bit of angle at down. 2. The ball will continue to move in a circular path if the total force is...

Imagine a pulley system, where a puck is connected by a massless string to a massless pulley that joins a mass m that's hanging at the end of the table. Would the force of friction change as you increase mass m , the object that's hanging? why so?

I am trying to draw an FBD for a beam leaning against a frictionless wall attached to a pin at the bottom end. The forces present would be the weight, normal force of the pin attached to the floor and the normal force of the wall. When determining forces that are present, can I remove the...

Anybody in here taking Physics class right now or in the past? Can you help me out...i have 4 more questions: 1) How much impulse stops a 50-kg carton sliding at 4 m/s when it meets a rough surface? Conservation of momentum: mv(befor) = mv(after) 2) If a Mack truck and Ford Escort have a...

I have a physics exam tomorrow and while recapping things for the exam, I was wondering one thing. The magnetic force exerted to a current carrying wire in a uniform magnetic field is \vec{F}=I \vec{l} \times \vec{B}. But a current carrying wire induces a magnetic field, so the magnetic field...

Homework Statement A train approaches, and passes through, a station. During this period the velocity of the train is constant and the engine is continuously sounding its whistle. Which one of the following correctly describes what an oberver on the platform will hear? Sound heard as...

Homework Statement I was just thinking about the fact that torque = rxF = I*alpha when there is no translation. Suppose that I had a lever (length 2r) with a pivot in the middle, and I attached a weight of mass m on the end. The torque would be rmg and the angular acceleration would be...

1. Can an object increase its speed if the magnitude of the acceleration is decreasing? I put yes because an object be accelerating at 50 m/s^2 and then decelerate to 40 m/s^2 but velocity would still increase. 2. Describe the motion of the object V parallel to a V anti-parallel to a...

Homework Statement A fisherman and his young daughter are in a boat on a small pond. Both are wearing life jackets. The daughter is holding a large floating helium filled balloon by a string. Consider each action below independently, and indicate whether the level of the water in the pond...

1. a force is directed 20 degrees from the horizontal on a 2kg object. At the top of its projectory, what is the magnitude of the force acting on the object. I said 19.6 N, because the only force acting there would be gravity, right? so 9.8*2 = 19.6 N 2. an object that weighs 3m explodes...

If a car is traveling at a constant speed up a hill, do you feel lighter, heavier, or the same Can an object have increasing velocity and decreasing acceleration

Question 1: I was told here that in Case A, the torque is equal to zero. I'm not really seeing that. I know torque is equal to rFsin\theta. If I draw a vector from the rotation point (the very center of the spool) to the point where the force is being applied, I get that the force and r...

so i understand how to resolve a limit at x->oo, but from a conceptual standpoint, i do not get it. for example, limit x->oo, 4x/5x so the answer is 4/5, but oo/oo is an indeterminate expression i understand that if i treat x as a variable, then it makes sense, but still if the example was...

Homework Statement Two batteries that have emfs E1 and E2 and internal resistances r1 and r2 are connected in parallel. Prove that if a resistor of resistance R is connected in parallel with combination, the optimal load resistance (the value of R at which maximum power is delivered) is given...

Homework Statement An object is moving to the right in a straight line. The net force acting on the object is also directed to the right, but the magnitude of the force is decreasing with time. The object will a) stop and then begin moving to the left. b) continue to move to the right...

Homework Statement This is conceptual question...Is work a scalar or vector quantity? Is it force times distance or displacement? And it just Fdcostheta by definition of the dot product. Why is it cos theta even when you calculate work done by gravity? Homework Equations Fdcos theta...

When a board with a box on it is slowly tilted to larger and larger angle, common experience shows that the box will at some point "break loose" and start to accelerate down the board. The box begins to slide once the component of gravity acting parallel to the board equals the force of...

I've been wrestling with this problem for a while, and I really cannot understand it. As I understand it, the limit of the resolving power of the eye is related to diffraction: when Rayleigh's criterion is just satisfied, then two objects which are close together can just be resolved, i.e. we...

For years I have been wondering why wind turbines are designed with very skinny blades (photo http://en.wikipedia.org/wiki/File:Turbine_aalborg.jpg ). Most of the available wind passes right through the circular "reach" of the device without touching the blades. Wouldn't it be more efficient if...

I am trying to prepare for a exam. It would be great if someone could help me understand these concepts. Thanks! When rounding a curve in your car, you get the impression that a force tries to pull you toward the outside of the curve. Is there such a force? A fisherman wants to reel in a...

Please answer as many as possible! Thanks! 1. If the kinetic energy of a particle is zero, what is its linear momentum? 2. If the speed of a particle is doubled, by what factor is its momentum changed? By what factor is its kinetic energy changed? 3. If two particles have equal kinetic...

Homework Statement If the projectile is launched and lands at the same level. Then the angle is the same at launch and landing, correct? And if the projectile is launched from a different height, then the angle of launch is different than the angle of landing? In such a situation, if it says...

Homework Statement A parallel-plate capacitor consists of two square plates, size L x L, separated by distance d. The plates are given charge +-Q . Each part changes only one quantity; the other quantities have their initial values. Part A What is the ratio E(final)/E(initial) of the...

Since I only got 1 reply on my old post (I think it is because my format is wrong) I am making a new post. Hopefully that is okay Homework Statement a) Person A and Person B are around the same size, they play tug of war. Both pull as hard as they can but none are winning. Compare...

Hey guys, I have a few questions about my physics homework. They are mainly conceptual and I have attempted them. I will write down the questions AND my attempts and please correct me if I am wrong. 1. In a situation of tug-of-war with a friend who is the same size and weight. You both pull...

I am working on a lab, and *think* I understand what is going on, but looking for a double check of my logic from someone more experience than I am. In short its a multi-piezometric tube venturi meter, with 1 throat near the begining, a couple of expansions, and a control valve near the end...

You let an empty suitcase swing to and fro at its natural frequency. If the case were filled with books, would the natural frequency be lower, greater, or the same as before? I thought that the frequency would be greater because there is more weight to push the suitcase back and forth. Is...

Electromagnetic waves!Conceptual help please! A long steel wire is cut in half is connected to a different terminal of a light bulb. An electromagnetic(EM) plane wave (E(x,y,z,t)=Esin(kx-wt)[y hat direction], B(x,y,z,t)=Bsin(kx-wt)[z hat direction]) moves past the wire. a) Suppose the wire...

Homework Statement QUESTION 1 :A stationary bomb explodes in space breaking into a number of small fragments. At the location of the explosion, the net force do to gravity is 0 Newtons. Which one of the following statements concerning the event is true? a) Kinetic energy is conserved in...

A thick spherical shell of charge Q and uniform volume charge density p is bounded by radii r1 and r2, where r2 > r1. With V = 0 at infinity, find the electric potential V as a function of the distance r from the center of the distribution, considering the regions (a) r > r2, (b) r2 > r > r1...

I need someone to point me towards an instance of a relatively simple QFT problem which illustrates what can be calculated from QFT, how it is calculated, and its physical significance. (Note the qualification "relative". I realize there are likely no simple problems in QFT.) If someone...

Homework Statement A ball is dropped from rest from the top of a building and strikes the ground with a speed vf. From ground level, a second ball is thrown straight upward at the same instant that the first ball is dropped. The initial speed of the second ball is v0 = vf, the same speed...

Need help in understanding the physics behind these physical moments. Can someone please help me how in terms of physics the following things happen? 1) Why does a rocket go up? (what I think is that force emmitted from the flames released from the rocket creates a force that heats the...

Following question is for concept only not an actual problem to solve. Saturated steam is flowing in a 3" diameter pipe under a certain pressure (saturation pressure), temperature and velocity P ,T, v . The 3" diameter pipe expands suddenly to a 24" diameter pipe that is 10 feet long. The...

http://wps.prenhall.com/esm_giancoli_physicsppa_6/0,8713,1115091-,00.html (under practice questions) On questions 16,17, & 18 I'm trying to figure what is the difference between them (Clearly Tc is different, but how does that change the problem?). The question asks The heat engine shown...

Imagine processing the gas clockwise through Cycle 1 and then counterclockwise through Cycle 1. Compare these two processes on the basis of the heat energy transferred to the gas in the entire cycle. Choose the correct comparison symbol. Q_clockwise for Cycle 1 <,=,> Q_counterclockwise for...

Homework Statement A rigid body is rotating about a fixed axis through the origin. The angular velocity is \omega\hat{k} where \omega is positive. What is the unit vector in the direction of the velocity of a point on the body located on the positive y axis? The Attempt at a...