# Physic Definition and 93 Discussions

A physic garden is a type of herb garden with medicinal plants. Botanical gardens developed from them.

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1. ### How do you know if the focal length is positive or negative?

In this problem, it doesn't tell you where is the focal length. So how do you know if it is in front or behind the object?
2. ### Confused about applying the Right Hand Rule (RHR)

the answer is attractive. but i don't see how this is how I draw mine and I use the RHR on the magnetic field between the two wire and I got the force is opposite
3. ### Studying Struggling to teach myself math and physics

Hey! I want to study physics and math, and eventually, I would like to get a Bachelor in Physics. I quit university about 5 -ish years ago, an Engineering major...I wasn't a good student and don't really remember anything. A couple of years ago I discovered a big interest in Physics and...
4. ### Help understanding "Heat capacity"

Homework Statement:: First of, this is not a "homework" per say, since this is not in my curriculum. If you still want to help, see the description :) Relevant Equations:: C = Q/(delta T), where delta T is the raise in temperature in Kelvin and Q is the added heat energy I want to learn about...
5. ### Find the acceleration in circular motion

Hello , First of all , I am still new to circular motion or any motions in general and still relatively learning so please bear with me. 1 . The direction of the tangential acceleration is parallel to the net velocity and that of radial of perpendicular to the velocity. So the direction of net...
6. ### I Magnetic Levitation Issues

[Mentor Note -- Two similar thread starts merged into one] Hey all, I have been working on this project for a while now, which features suspending an object midair through the use of magnetic levitation principles. Cool right? And so I have been researching and trying, even finding ground...
7. ### Quick question about which radius to use on Gauss' law problem

confused on part A/B when I look up they did E= Q/2e(0.8)^2. But why not use the 0.100mm because that is the area of the enclosed. Same with B why did they use 100m and not 0.8m because 0.8 is smaller so it enclosed the charge

Electric Flux = E*A = 5*6(0.05)^2. when i look up at other sources they use Electric flux = q/ (8.854*10^-12 [this is e]) equation but im confused on why the E*A equation don't work. The answer is 0.02Nm^2/C
9. ### Engineering Acceleration Engineering First Semester

The function x (t) = 4 (m · s) t − 1 + 10 m describes the position of a mass point. In which direction does the speed point at time t = 1 s? Is the amount of speed constant or not? does the velocity function change its sign for t> 0 at some point? And in which direction does the acceleration...
10. ### Thermodynamics: Ideal gas model

Do particles have air in between them in the ideal gas model? I think the answer is 'no, but I am not quite sure about the explanation. Is it because in an ideal gas model, the volume of the particles is negligible? Thank you.
11. ### What velocity does the particle need to get to point B?

It was a long time ago I did these kind of problems so I’m a bit rusty. The only thing I can think of is divide it up to two parts one x and one y. In y the acceleration is sin(a)*9.82? Then put that in the equation and solve for t. In x the there is no acceleration so the formula is x=V0*t, I...
12. ### How far can the person climb up the ladder before it starts sliding?

Look on picture two for my equations, I’m pretty sure my first three equations are correct as it’s the same on the answer paper I got. Answer paper only shows the three equations and correct answer so I have no idea how they got to it. When I put the equations togheter And solve out ”h” i get...
13. ### What is the resulting force between the beam CB and E?

I assumed that the vertical force at point B would be the same as the force between beam CB and E because of newtons law. Did I assume wrong? Look below for my calculations and answer which I got to 250N. I don’t know the correct answer but assume someone here can tell me if I solved the problem...
14. ### B Does a rubber mat on a device prevent static build up

Does a rubber mat on a device prevent static build up and discharge on a metal device well using it
15. ### Clearing for b in a formula

the equation is not equal not to anything (example: 3x = 6) and i don't know how to resolve [e ^ - (b / 2m) t].
16. ### I The solar system and the Coriolis effect

After concluding an investigation about the coriolis effect, I wondered how this phenomenon affected the solar system and in particular the moon. Since the moon is a body that moves within the rotating system formed by the sun and the earth, an apparent deviation in the moon's path would be...
17. ### Α baseball player throws the ball...

Hi all ! I wonder if I'm right. (From : Fundamental University Physics, Volume 1 (Mechanics) - (Marcelo Alonso, Edward J.finn) Addison Wesley 1967) This is my try: * I have the Greek version of the book and there is no answer. Thanks.
18. ### Which of these methods of propulsion is “best” for future spaceflight?

Summary: Which of these hypothetical propulsion methods is the best for a spacecraft during Interplanetary flight? Let’s just assume all at this point are cost-effective at the time. Consider the •Safety of the engine •The speed •The efficiency 1.) Monoatomic hydrogen propulsion 2.)...
19. ### Calculating the coefficient of friction Given 2 forces and and angle

i tryed putting all the number into that equation but it does not work, i have no clue if i need to include the angle to solve this or not and if i do i have no clue how i would
20. ### Vectors Homework

Can’t seems to find the degree
21. ### Electric field at the point P

I got the answer: E(P)=(k*Q)/(3î )−(k*Q*ĵ) /2 Can someone confirm if this is the right answer?
22. ### I Unknown formula

What is this formula? q=λ⋅S⋅∪_x What does s and lambda mean?
23. ### Law of conservation of angular momentum

Given the figure, how can i arrive to this formula knowing that angular momentum is conserved? I know that p = mv and L = p x r. So the initial momentum will be L1 = mV x R and the final momentum will be L2 = mv x r. I am not sure how R will equal to b since the distance between the...
24. ### Measurement of temperature

What is the difference in temperature with different thermometers for the same object? Thanks !
25. ### Definition of work done by torque

I' m trying to derive the work done by a torque from W = ∫ F ⋅ ds and I' ve looked up the internet, it said: W = ∫ F ⋅ ds ( since ds = dθ × r ) ---------------------------------------- ( Line 1 ) it can be written as W = ∫ F ⋅ dθ x r this is a vector triple product , thus can also...
26. ### Short conceptual question on Work, Energy and Forces

Homework Statement (Please check the attached image) 2. Homework Equations The Attempt at a Solution Those are my answers. I thought the magnitude of the applied force would be bigger because that would be responsible of keeping the block on that spot without having it pulled back by the...
27. ### Calculate the mass when not hanging it in dynamometer

Homework Statement Hello! I have a physics problem that I can't solve. I'm supposed to describe how I can calculate the mass when knowing the µv (I don't know the english term but i'm guessing friction...something (friction when the object is not moving)). You are allowed to use a dynamometer...
28. ### Teaching high school students for the first time

Hello, I have been accepted for a physics teacher position in a high school. This would be my first job ever. I taught "tutored" students before in my home university for two semesters, and I think I am a good teacher. But, I feel that teaching high school students is totally different. I am...
29. ### A Absorption spectrum

Hi everyone, I have an absorption spectrum that I obtained from a sample after radiation and I need to use the background sample as a reference, how can I do that using excel? what I did is subtract the radiated from the background spectrum then plot it, is that right? Thanks.
30. ### Find the minimum distance between 2 particles

Homework Statement A point particle of mass m and charge q(>0) approaches to a point particle Q(>0) at a fixed position. When the distance between the two particles is L, the speed of the moving particle is v. The permittivity of the vacuum is denoted as Epsilon0. Find the minimum distance...
31. ### Can the only reaction force (to gravity) be friction?

Homework Statement If you have an object say in a vertical pipe, which only has a gravitational force acting on it would the reaction forces only be friction forces? If this is the case how would you calculate the forces? would you calculate the friction force using the friction coefficient or...
32. ### Does the angle of a beam fixed at two points affect the method?

Homework Statement if a beam fixed at two points is on an angle say 45 degrees from the x or y axis instead of running parallel to x axis in most questions does this effect calculations? The force acting upon it would be a load directly downwards Homework Equations N/A The Attempt at a...
33. ### What is this error in Maxwell Ansys -- 'Transient solver handles only isotropic conductivity!'

Hi, I am working on Maxwell version 17. I have a simple motor to analysis 2D FEM. However, when I analyze the model, I see this error. "Maxwell2d solver, process solver2d error: Internal Solver Error: 'Transient solver handles only isotropic conductivity!'. (7:07:10 PM Apr 16, 2018)" I am...
34. ### Other Can a physicist study evolutionary biology? How can I do?

Hello, I’m an undergraduate physics student. Recently, I recognize that I am interested in evolution and I want to study life’s origin. When I preferred physics, because I want to learn how nature works. Now, I am not only interested in how nature works, also I’m passionate for neuroscience and...
35. ### Understanding Bernoulli's Principle

My understanding of Bernoulli's Principle is something like this: Pressure is inversely proportional to velocity. Fluid flowing through smaller cross-sectional area has increase velocity & decrease in pressure. Also P = F/A.... so would force also decrease for fluid going through small area...
36. ### What is the Significance of the Electric field in a closed circuit

Hi, I am confused about the electric field lines which are depicted mostly on the Internet as per conventional way. What I understand that the conventional current was due to positive charges which was wrong. Actual flow of the current was due to the negative charges or electrons. When the...
37. ### Find the current induced in a wire loop by a nearby current

Homework Statement Homework Equations The Attempt at a Solution When the circuit moves creates magnetic force that moves the some charges in the wire and that is a current. That is what i thought. F = Q.v B sin theta B = ( permeability Of vacuum* I)/(2pi.r) But how to find the I? Thank...
38. ### Question about vacuum powered projectiles

I'm writing a novel and wanted to research a possible weapon I came up with to make sure the physics are at least possible. However, I could not find anything on vacuum-based projectiles other than ping-pong balls, while this is interesting, but it doesn't answer my question on what would happen...
39. ### Physics help to measure friction

<Moderator's note: Moved from a technical forum and thus no template.> Here’s the question Design a simple expirament that you could carry out in your own home to i) determine coefficient of friction between your object and surface ii) prove that coefficient of static friction is only...
40. C

### What is Rotation

As a student taking my first step into rotational physics in a classroom filled with students who have a year of this ahead of me I beg for help! :P So what is Rotational velocity? What does it define? How do signs work with rotation? What does its acceleration mean? Angular Velocity is...
41. ### The equation to find the frequency of a bouncing ball

[Mentors' note: No template because this thread was moved from the General Physics forum] Ok so first of all believe me i would not make a new post if i found the answer anywhere online but i i couldnt find it. Right now i am doing an experiment to find the frequency of a bouncing ping-pong...
42. ### Examine the following circuit. Now complete the table.

Homework Statement Homework Equations The Attempt at a Solution
43. ### How exactly do motors and generators work by using magnetic fields?

So I know if you move a charge in a magnetic field it induces voltage and hence a flow of charge is created which is current. ( Please correct me if I'm wrong). But that's pretty basic right. However, I'm having trouble understanding the use of split rings in the functioning of a motor. I would...
44. G

### Programs Should I pursue a Physics Major?

I am currently in 9th grade and have been into astronomy and basic physics for a few years now. I'm thinking about (once enrolled obviously) majoring in physics. Only problems are: 1: Pretty good at math but struggle a bit and end up forgetting a lot of information (at least in algebra) and I...
45. J

### Maximum height a waitress can push on a glass without it tipping

Homework Statement I have attached the problem. I will write it out: A waitress attempts to push a glass of water of heigh 15.o cm and diameter of 7.00 cm on a dining table, as shown in the figure. If the coefficient of static friction between the glass and the table's surface is 0.350, what...
46. ### B Condensaion / clouds

I understand that condensation occurs when water (in gas form) looses energy and becomes liquid. What I don't understand why some surface is needed to form a liquid water
47. S

### Calculate charge and capacitance

Homework Statement Three capacitors are connected in series, C1 = 4.5 mF, C2 = 7.5 mF, and C3 = 10 mF, and connected to a 150V d.c. supply. Calculate: (a) the total capacitance...
48. ### I Can a particle cause a Bose-Einstein condensate to wave?

Could a particle move through and displace a Bose-Einstein condensate, causing it to wave?
49. ### Newton's laws of motion -- Constaint motion

Homework Statement In the following diagram a massless pulley is pulled by a constant force of magnitude P. There is no friction between the block and the floor. The acceleration produced in the block if mass m is? PIC ATTACHED Homework Equations Took a1/2=a2 where a1 is accn of block and a2...
50. ### Engineering Problem with series RLC circuit and dependent source

Homework Statement here is my problem : Homework Equations like usual, the problem is related with RLC circuits and transients The Attempt at a Solution [/B] from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4....and from the...