The major unsolved problems in physics are either problematic with regards to theoretically considered scientific data, meaning that existing analysis and theory seem incapable of explaining certain observed phenomenon or experimental results, or problematic with regards to experimental design, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.
There are still some questions beyond the Standard Model of physics, such as the strong CP problem, neutrino mass, matter–antimatter asymmetry, and the nature of dark matter and dark energy. Another problem lies within the mathematical framework of the Standard Model itself—the Standard Model is inconsistent with that of general relativity, to the point that one or both theories break down under certain conditions (for example within known spacetime singularities like the Big Bang and the centres of black holes beyond the event horizon).
Question:
A square frame of side 10cm rests on a table. Confined within the frame are 500 ants, each of mass 0.001g. The ants rush about randomly with constant speed 0.02m/s, colliding with each other and with the walls. Assuming the collisions are perfectly elastic, calculate for force on each...
Derive an expression for the number of impact of gas molecules on unit area in unit time in terms of the number of molecules per unit volume, n, and their mean speed, <c>. Explain the assumptions you make.
A disc of radius "a" rotates with constant angular velocity "omega" in a gas at low...
(i) Use this information to deduce a value for Avogadro constant.
(ii) Draw up a table showing the numbers and distances from P of the sodium ions in positions similar to ion A, the chloride ions in positions similar to ion B and the sodium ions in positions similar to ion C. Hence find an...
First of all I have been searching everywhere over the internet for help. My son is asking me for help with his physics home problems and I want to teach him but I don't know how to solve any of these could someone please help me and solve these and post how the solved them and what equations...
Having significant issues with solving these problems. Any help is appreciated. Thanks to all who can help!
1. How large must the coefficient of static friction be between the tires and the road if a car is to round a level curve of radius 75 m at a speed of 90 km/h?
I used the...
1. a ball rolls of off the edge of a table top 1m high and strikes the floor at a point 15m horizontally away from the edge of the table. find (a) the time of flight (b) the initial velocity and (c)
2. a boy throws a ball upward into an improvised basketball ring at an angle of 60° from the...
Homework Statement
1) The horizontal slot guide C moves downward at a constant velocity of 4.00 in/sec. Crank OP (radius rOP) is pinned at O and point P slides freely in horizontal slot guide. At the instant shown determine:
a) θ’ (The angular velocity of OP)
b) θ’’ (The angular...
Homework Statement
A 2.00 kg box is moving to the right with a speed of 9.00 m/s, on a horizontal frictionless surface. At t = 0, a horizontal force is applied to the box. The force is directed to the left and has a magnitude F(t) = 6.00 N
A) What distance does the box move from its position...
Homework Statement
Secret Agent Jane Pond is testing out a new particle ray gun. She knows the particles in the ray have charge -2e and a mass of 50u. (u = atomic mass unit.) To determine the speed of the particles in the ray, Jane needs a region of uniform electric field. She takes...
Homework Statement
Please refer to the figures. (The first one is multiple-choice, the latter is structured).
Homework Equations
For the first problem:
u = √(2gH)
x = uxsinθt + \frac{1}{2}gsinθt2
uycosθt = \frac{1}{2}gcosθt2 and maybe others
u = initial velocity
x = x-displacement...
I am a CIE A Level student and the following question is of 1st year undergraduate level.
A bag containing a mass M of sand is suspended from a hook on the arm of a balance at a height h above the balance pan. At a time t=0, the sand starts to pour from a hole at the bottom of the bagm...
How exactly would be the best method in approaching them? It is not so much solving them that bothers me, but the fact that I am pressed for time. It becomes infeasible to draw diagrams, free-body/motion diagrams, listing knowns and unknowns, and then starting the analysis to solve 1 out of 13...
Hey, I don't really know where to post this, so I'll just post it here. Does anyone know some websites, which contain a list of problems to do with classical physics? Something like http://projecteuler.net" . I want these sorts of problems, except for classical physics.
I don't really want...
When I do Physics Problem, I can't find the solution, so there are two groups of people tell me to do difference things.
1. Do not open solution manual because it will block your imagination for doing physics problems.
2. Just open it and it will give the way to do another physics problem by...
I'm not sure if this is really the right forum for this, but the other forums insisted that all homework like posts should go here.
In his book "How to think like a Mathematician" Kevin Houston says that the best way to learn a subject is to create your own problems, since doing this requires...
Can anyone give me some helpful advice as to how to improve my problem-solving skills?
Please help me out. I'm currently taking a 1st year (undergrad) level Physics course. I do well on my assignments for the most part, and occasionally look for help on these forums to find approaches to...
I'm searching a book, or a place on the net where I'll find tons of examples of numerical problems in physics (mainly quantum mechanics) written in Python.
I have tons of books about Python, but none have good examples on problems like tunneling, solving Schrodinger eq for various potentials...
Homework Statement
1.) How fast must a rocket leave the Earth’s surface to reach a maximum height of 895 km above the surface of the Earth (assume the rocket is simply going straight up)?
The answer is 3920 m/s
2.) How fast must a rocket leave the Earth’s surface to reach an orbit with...
Hey everyone. I was wanting to know if anyone knew of a website (preferably free) where someone could go to get some good practice problems for introductory physics. We have a test coming up this week and I would like to just get some extra practice in (trying to pull my grade up from our last...
Could anybody suggest a source of physics problems similar to those found at the following link:
http://www.solvephysics.com/index.html
The problems provided at this site are what I require but a difficulty that arose when trying to purchase their material is proving difficult to resolve...
Hello,
This is my first post and I hope it's not incorrectly placed...
Recently I made the naive decission to design a water balloon trebuchet as a pet project. Furthermore, I wanted to calculate the exact specifications of the design ( counterweight, arm lengths, ect.) using only the...
The professor and my text aren't exactly doing it for me when it comes to my conceptual understanding of physics. I find myself getting frustrated when it comes to certain problems, mainly because the only thing standing in the way of me getting the right answer is how I set up the problem...
Homework Statement
1. What amount of energy is released whan 10g of steam at 100 degrees C condenses and then cools to water at 0 degrees C?
2. 1840 calories of heat is added to a 300g block of ice at 0 degrees C. what amount of ice melts?
3. 3600 calories of heat is removed from 5g of...
I'm in high school and am very frustrated by how easy "physics" is. I really enjoy the subject but feel it's watered down in my school, and apparently my state.
I would like to do some more complicated problems that only cover intro to physics, but are very complicated in that you need to...
I'm currently taking a Calculus Based Physics course. We have an exam in a few days. Although I understand the material well and have performed many textbook problems, my teacher is known for putting challenging questions on the exams. My Prof. writes his own exams, so they are not based on the...
I'm having trouble approaching this problem. I'm not sure how to set it up. Any help would be appreciated especially with necessary formulas and equations. Thank you.
A particle moves in the xy plane with constant acceleration. At time zero, the particle is at x = 7.0 m, y = 9.0 m, and has...
1. A bucket of mass 4.03 kg is pulled by a rope and accelerated straight upwards at a rate of 1.62 m/s2. What is the tension in the rope? Express your answer in Newtons.
2. Two masses are connected by a light string and pulley as shown below. The mass on the left is 2.34 kg and the mass on...
Physics help!?
Homework Statement
A skydiver has mass of 75g, traveling at 80mph, drag force on skydiver is 650N. Find acceleration of skydiver at 80mph (g=10n/kg??)
Homework Equations
Do I use a=f/m
The Attempt at a Solution
No attempt - I am really stuck!
Help me please!
Homework Statement
Q1.A person of mass 80kg is traveling in a car with a velocity of 25m.s the car is involved in a head on collision and brought rapidly to a halt. Neglecting frictional forces effects. Calculate (a) a person momentum just prior to impact (b) the resulting...
I'm a 3rd year physics major and my friend is a 3rd year computer science major, and for a bit of fun we want to do some sort of project that will utilize both of our skills. Some sort of computational physics problem seems appropriate, but with my limited knowledge, it seems that a lot of them...
1.
Homework Statement
Determine the x and y components of the following three vectors in the xy plane.
(a) A 9-m displacement vector that makes an angle of 35° clockwise from the +y direction.
x: ____ m
y: ____ m
(b) A 25-m/s velocity vector that makes an angle of 45°...
1. Four small balls of identical mass 2.36 kg are arranged in a rigid structure as a regular tetrahedron. (A regular tetrahedron has four faces, each of which is an equilateral triangle.) Each edge of the tetrahedron has length 3.20 m. What is the moment of inertia of the system, for an axis of...
Homework Statement
You throw a ball toward a wall at speed 24.0 m/s and at angle θ0 = 41.0° above the horizontal (Fig. 4-35). The wall is distance d = 21.0 m from the release point of the ball. (a) How far above the release point does the ball hit the wall? What are the (b) horizontal and...
1. A parent pushes a baby stroller from home to daycare along a level road with a force of 38 N directed at an angle of 30° below the horizontal. If daycare is 0.83 km from home, how much work is done by the parent?
(38N)(cos(-30))(.83km or 830m)=?
2. You have a 0.750 kg picture frame on a...
i have a problem about my physics 21 and i don't know how to approach it..
Problem says that : a car is driven up a steep hill at a constant speed. discuss all the forces acting on the car. what pushes up the hill..?
Thanks
I'm going to be tutoring HS students (junior and senior) in physics soon enough. I need to have a good, comprehensive source of problems. Any suggestions?
Hello Everyone,
I am having difficulty with these selected problems. Attached is a link to the diagram in reference to each problem. I would truly appreciate your help! Thank you!
1. In Fig.1 the scale at the left is attached to the ceiling and a mass of 1.00 kg hangs from it. It reads 9.81 N...
1. Two carts, one of mass M and one of mass 2M, are sliding on a horizontal frictionless surface with the same initial kinetic energy. A constant force is applied to each cart in order to bring them to rest after the same distance. The less massive cart requires a larger force to come to rest...
Physics Problems ? (particle acceleration)
I'm working on my last 2 of 30 or so physics problems and am pretty lost on what to do/how to even start. The homework is due in exactly 3 hrs, I already have an "A" on this assignment but would like to squeeze on these last 6 points or so.
Question...
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...
Hi, I get really confused when to use the cos function or the sin function. for example, I was looking at this yesterday and thought the other way around of the correct answer. Why did it chose sin function for tension and cos function for the normal force?
This problem doesn't explain why it...
In Physics I have a C average right now. These two quizes are my last chance at bringing my grade up to a B for this class. I have attached a copy of all of the problems that are on these two quizes totalling seven questions. THis is open book take home quiz where we can work with whoever we...
Homework Statement
I've been absent for quite a bit in school and I have a lot of homework and catching up to do. I've been looking for many resources at hand which can help me understand these problems but so far the book is not helping me. I missed some of the vector lessons, a lot of the...
I have a test in a day and I basically know almost everything. We were handed out a packet of about 50 questions for practice. I've gotten everything but these 6 problems.
I have the answers, but I'm clueless on how to get them. I have an A average in Physics AP and would like to keep that...
Homework Statement
Hi I'm having trouble with these problems. I'll greatly appreciate it if someomne could assist me.
1) A certain wave-propagating system has a dispersion relation that can be expressed by omega^3*T^3=k^2*L^2 where L and T are given constants.
Note: omega is a greek...
1.
Calculate the orbital period for Jupiter's moon Io, which orbits from the center of the planet.
2.
A white dwarf is a collapsed star with roughly the mass of the Sun compressed into the size of the Earth. What would be (a) the orbital speed and (b) the orbital period for a spaceship...
PLEASE HELP I'M CLUELESS ON THESE PROBLEMS
FOR THIS QUESTION I FOUND B BUT I HAVE NO IDEA ON HOW TO FIND A.
A plane weighing 220 kN (25 tons) lands on an aircraft carrier. The plane is moving horizontally at 62 m/s (139 mi/h) when its tailhook grabs hold of the arresting cables. The...
A Few Tough Physics Problems! I'm stuck, Please Help!
1. Two canoeists in identical canoes exert the same effort paddling and hence maintain the same speed relative to the water. One paddles directly upstream (and moves upstream), whereas the other paddles directly downstream. With...
Homework Statement
1. If you are driving 70 mi/hr and you look to the side for 2 seconds, how far did you travel during this inattentive period?
2. A pilot determines that his plane can accelerate at a rate of 10,000 mi/hr². If the runway is .5 miles long and he must be traveling at 100...
REALLY URGENT! Please help me with these Physics problems!
Question1: You are driving down the road in your car and you notice that your favorite radio station that you are listening to, 95.7 MHz, is going in and out. You look out and over and you see two long buildings with a gap in them. You...