Basic physics Definition and 150 Threads

Some silly questions I've just never been able to figure out, and it really bothers me when I don't know if something is a concept like speed, or just a way of describing something else and not in itself tangible. If anyone could take the time to clear these (or some of them) up for me, it would...

Homework Statement Two bodies of masses M1& M2 resting on frictionless surface. Bodies touch each other without any friction. What will be the force between the bodies, If they are pushed from one end with force F and both are accelerating towards other end? Answer given is (M2 x F)/(M1+M2)...

Homework Statement A small object, of mass 0.02Kg is at the top of a tall structure 160m high, it is dropped from rest. Ignoring air resistance.. 1. Find the speed of the object as it hits the ground 2. find the time taken Homework Equations So far we have learned the equations...

Ok, new to the forum and taking my first real science credit physics course (I have taken one prior but it doesn't count towards the major). I'm in somewhat of a bind here as i just got a TI-89 titanium thinking that more was inherently better, I am now regretting this decision. When i go to do...

Hi guys, i'd really like to understand physics but for some reason I'm not coping. Not sure if it's the calculations or something. But I'm willing to learn, I'd appreciate some help with this problem:Homework Statement A B string on a guitar with a length of 33cm is held fixed at both ends...

Does anyone know a good website or other source for practicing conversions and really just units in general? I'm having trouble with them, I'll give you an example problem I did to illustrate my problem... What is the pressure at a depth of 5 meters in alcohol? (The specific gravity of...

Ok, Please correct me if I'm wrong; Flux lines are a sort of mathematical visualisation of magnetic fields, they do not exist. As such, there still exists a magnetic field between flux lines (?), just in calculations we use flux lines because they are simpler (?). In voltage transformers...

Homework Statement the man having the weight of 75kg is able to run up a 4.5 m high flight of stairs in 4s. determine the power generated. how long would a 100w light bulb have to burn to expend the same amount of energy? Homework Equations The Attempt at a Solution I havnt done...

Hi, I am a primary school teacher and have just been observed by my headteacher and a "senior consultant" in a lesson on sound. I asked the children to find the best insulator of an alarm clock from a range of materials wrapped around it. The material that worked best was the newspaper...

Homework Statement A straight, nonconducting plastic wire 8.00 cm long carries a charge density of 125 nC/m distributed uniformly along its length. It is lying on a horizontal tabletop. A) Find the magnitude and direction of the electric field this wire produces at a point 5.50 cm directly...

Hi. I'm trying to understand a couple of things. When you put a piece of metal on, say the cathode of a battery, I suppose there is a charge transfer from the battery to the metal because the electrons on the cathode have a high potential energy? And so if I connect a piece of metal to both...

Basic physics question? Homework Statement My younger sister has a problem stated: "An electromagnetic wave is found to have a frequency of 7.8x10-10 Hz. What is the speed of the wave?" Homework Equations The Attempt at a Solution It's been a while since I have done this...

Homework Statement A 28.0-kg block is connected to an empty 1.00-kg bucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.450 while the coefficient of kinetic friction is 0.320. Sand is gradually added to the bucket until...

Homework Statement A baseball is hit at a height of 1m with an initial speed of vo module at an angle of projection of 35o from the horizontal. She spent just over an obstacle of 29m high at a horizontal distance of 64m. Find a) vo b) the time it takes to reach the OBSTACLES c) its speed...

A certain light truck can go around a flat curve having a radius of 150 m with a maximum speed of 35.5 m/s. With what maximum speed can it go around a curve having a radius of 79.5 m? Answer is 25.8. I was trying to use the relationship of V=RW but I can't seem to figure out this simple...

Homework Statement If mu = 0.2 find the maximum angle before slipping occurs Diagram: A ramp in the shape of a right triangle that is 30 degrees above the horizontal. A mass is on the ramp and tied to it is a string that runs around the ramp to the vertical side of the ramp where another mass...

Can you help me out and tell me if I am right or wrong when I say the following: Think of a free fall. As we see something in a free fall here on Earth we are really seeing/experiencing it in 2d not 3d. An object that moves in a straight line from one point to another is traveling/falling...

Homework Statement I already know the answers because this is a review sheet, but I don't understand how to solve number 1, and I don't understand the wording of number 2. 1) A particle is moving along the x-axis and has a position given by x=(24t-2.0t3)m, where t is in seconds. How far is...

I'm 53 and know very little about Physics and want to start to learn from the very basics. I will be learning entirely from home by books and the internet. Can anyone recommend a very basic beginners book to start learning from (UK publications prefered), please assume I know nothing :D...

Hi I have a few questions: 1) If a rigid object was dropped (and its mass, initial height are known) what would the shape of the Force-time diagram look like and how to find the maximum force? 2) If an elastic object was dropped knowing only initial conditions is it possible to predict...

Homework Statement 1. A frictionless slope has a hypotenuse of 2.0m and a height of 1.0m. A box of mass 40kg is pushed up along the hypotenuse with a force of 250N. Since work done is defined as the product of the force and the distance moved by the object in the direction of the force, we...

Hello all. Firstly, I want to note that I'm sure you've all heard this question multiple times but I don't know what search phrases I would use to find it - so I'm sorry for asking a boring basic question. OK, I'm learning extremely basic introductory physics and I was having a look at...

Homework Statement How much heat is released freezing 75 grams of steam at 110 degrees celcius into ice at -5.1 degree celcius Homework Equations The Attempt at a Solution I tried to do this problem but got an answer like -17101.6J. I don't need you guys to give me an answer but...

Homework Statement If a tennis ball with a mass of 57 g is shot out of a spring cannon at a 45 degree angle and goes 10m find the answer to the following questions: What is the velocity. What spring constant must the cannon have. What would be the constant converted into lbs/in.Homework...

I work for a museum, and I want to create a sort of "ear trumpet" or reverse megaphone for children to use. The purpose is to show how some animals, like owls, have super hearing. I have a sheet metal manufacturer who can create it. I'm just not sure what the dimensions of the larger hole and...

Hi, I'm new here but want to get to know physics fairly well. This might sound strange, but I'm still in Middle School. My real interest in physics is to get to know QM, but I know I have to start somewhere :P. My interest in physics began with a small group that learned from a college...

Homework Statement A very heavy wall moving at 60mph, a ball moving same direction at 120 mph. What is direction and speed of ball after ball hit wall. Homework Equations I am thinking to use the momentum conservation: mass of ball*velocity of ball+mass of wall*velocity of wall don't...

Homework Statement in the design of a spermarket there are to be several ramps connecting different parts of the store. customers will have to push grocery cats up the ramps and it is obviously desirable that this is not be too difficult. The engineer has done a survey and found that almost...

Branden runs for a ball from a dead stop. It takes him 3 sec to reach it after traveling 10 meters. What was his average acceleration? What velocity did he achieve when he caught the ball? Thank you!

Homework Statement You place a book flat on a table and press down on it with your right hand. The hand-to-book and table-to-book coefficients of kinetic friction are 0.47 and 0.44 respectively. The book's mass is 0.84 kg and your downward push on it is 9.00 N. Now, you use your left hand...

Might be some simple questions for you guys but I'm just in grade 9 1. Do isolating transformers change the voltage in a circuit? What I know is that isolating transformers have the same amount of coils because it needs to be safe. 2. Explain why an isolating transformer is often used...

A conducting bar of length L = 21.2 cm and mass M = 60.0 g lies across a pair of conducting rails. The contact friction between the bar and the rails is negligible, but there is a resistor at one end with a value R = 30.0 Ohms. Initially the rod is given an initial speed of v0 = 64.0 meters per...

I'm having to do a project and i got to do a detailed presentation describing and explaining the basic physics principals for gps's, tv's and radio. Each section has to be around 3-4 minutes of explanation. Im hitting a big rut with trying to find research for it. Also I am in gr.12 physics...

Hi Everyone! I'm new to this forum, and English isn't my first language - I would really appreciate your help with this question :) Homework Statement http://img225.imageshack.us/img225/3807/1milliontotheground.jpg there are given 2 thin shells with radiuses b and c, and a full sphere...

Acceleration question BASIC PHYSICS HELP :( Question1: A ball rolls with an acceleration of 20.5m/s^2. If it stops after 7s, what was its initial speed ? (Answer 3.5 m/s ) Question2: A wheelchair marathoner has a speed of 5m/s after rolling down a small hill in 1.5 s. If the wheelchair...

This may be a long read. Giving you a heads up :zzz: I am trying to achieve as many opinions as possible to figure out if this problem is simply my own or the teaching style does not agree with the way I learn, maybe i simply do not belong in science. It is past the drop the course point, so...

Harder Basic Physics Question..Please Help! Homework Statement A Perfectly hemispherical dome with a 10. meter radius is treated with a frictionless coating. A marble and a coin are released from the top of the dome simultaneously. We will assume there is no air friction. The coin will...

8. If the displacement of a car was 150 km [E] and the velocity was 50.0 km/h [E], what was the time of travel? A. 100 h [E] B. 3.0 h C. 100 h D. 3.0 h [E] (I divided 150 by 50) 9. The airport is 60.0 km away and you have 1.00 h to get there. If your speed for the first 40.0 minutes...

Homework Statement you are a crime scene specialists. a car in an accident had skidded to a stop and left tire tracks for 32 meters. The coefficient of sliding friction between the tires and road is .45, and the car's mass is 1000kg. Was the driver exceeding 25mph (11.3m/s) speed limit...

1. The car is stuck and the driver is trying to pull it, by pulling the rope in the center. I need to know with what force is the rope working on the car ? 2. F1^2 = (h/2)^2 + l^2 3. I pretty much failed sorry for my bad english. Please, I need this answer ASAP

Hey guys! This is my first post on this forum, though I've been looking through it for a few months now. I am in a basic Grade 11 physics course, and I'm having a little trouble with this one. So, here goes... Homework Statement A cannonball (mass=15.5kg) is shot out of a cannon on Earth...

I am trying to design an apparatus which will hit a marble a horizontal distance of from 1.5-1.6m every time. I have to calculate the force I need to hit the marble, but I can't seem to find an equation which works. If it helps any, the mass of the marble is 3.56g and I'm using a hammer which is...

Very Basic Physics...that I'm struggling on... Homework Statement In an experiment to find the temperature of a Bunsen flame, a 0.2kg brass mass is heated in the flame. The hot mass is then placed in a beaker containing 0.2 kg of water. The temperature of the water rises from 20C to 80C...

In this pic: http://img268.imageshack.us/i/imgp2719d.jpg/ I couldn't follow what's in the red box. I just hope anyone on here could look through it and tell me if there is some error in there. If not, then I feel stupid.

A 71.8-kg skier coasts up a snow-covered hill that makes an angle of 25.1 ° with the horizontal. The initial speed of the skier is 8.84 m/s. After coasting a distance of 2.10 m up the slope, the speed of the skier is 3.41 m/s. (a) Find the work done by the kinetic frictional force that acts on...

I have always wondered about this particular problem, when three electrons are arranged in a triangle and the question was to calculate the force experienced by one of the electrons. My physics teacher taught us that we only care about the forces colored in red and blue, totally ignoring the...

QUESTION 1 Homework Statement A guitar string is 0.70m long and is tuned to play an E above middle C (330 Hz). How far from the end of this string must a finger be placed to play A above middle C (440Hz) Homework Equations \lambda = 2L/n \lambda = v/f v = \lambda x f The...

I just want to make sure I know these things correctly for an upcoming test, so if anyone can let me know, correct me (especially on the bolded stuff), or give me some extra info, that'd be great! -Music has a constant waveform (sinusoidal), meaning it consists of musical notes with constant...

Homework Statement A particle is moving along a straight line such that its acceleration is defined as a = (-2v) m/s^2, where v is in meters per second. If v = 20 m/s when s = 0 and t = 0, determine the particle's velocity as a function of position, and the distance the particle moves before...

Hi guys,i'm happy to join you. I have the problem shown below for homework and i don't know how to solve it. This is becouse i have missed a lot of lessons during this month becouse of an illness. I will apreciate it if anyone can help me with the problem. Thanks. Problem: Two blocks, one...