Classical Physics

I have this problem I need to solve. I am trying the find the tension T in the cable. The weight M is 245.25 N and the force P is 147.15 N. If you don't understand, it's a rope attached to the roof, passes down into a pulley and then back up it, with someone pulling with a force of 147.15 N. The weight attached to the pulley is 245.25N. So, what's the tension and how do we find it?

Does gravity pull mass straight down, or does it pull it down in a spiral configuration to a central point? Also what is the smallest unit of mass that can have a gravitational force? And does gravity affect black holes? Meaning do blackholes also revolve around larger objects due to gravity?

So, I have to create a question in relation to vector components and figured before I go to do the tedious work in which my teacher has asked of us (anwsering the question using a scale vector diagram, algebraic method, and component vectors), I thought I would ask if the question is capable of being anwsered. The requirements of the question involve it being non-co-linear, no right angles, and determining a change in acceleration.... So, this is what I produced: Othello went to an abandoned soccer pitch one evening to hit some golf balls. The soccer pitch is 300 yards in length with houses on its receiving end. Bob, unconcerned with the possibility of striking a h…

Does anybody knows about a material (media or cloth) that allows the molecules of water to pass through but not the air (normal air). Thanks JP

sound is a wave. the inner ear detects sound by the vibrations on the eardrum from the sound wave. light is a wave also. does the moving of the eardrum to make a vibration imply that the sound wave has a mass and is pounding against the eardrum? wouldnt this mean that the wave has a mass? if light to is also a wave using this analogical thinking wouldnt this to imply that light waves have a mass? this doesent make sence why light is so different from sound of there both a wave- you cant get very much simpler defintion of the two than a wave- now so you dont think im retarded i do realise that light has no mass bc if it would every time we step out of the dark we …

Ok I have a question about a spinning circle. How can a circle spin round? I know it sound weird but I while on a merry-go-round it hit me that the outside of a circle has a bigger circumference than further in the circle, so wouldn’t the edge of the merry-go-round have to be moving faster than the centre of the merry-go-round because it has a bigger distance to travel than the centre does. To try and put it more simple, if the circumference of a circle is 10cm then further in the circle there would be a circumference of 5cm but for the circle to do a complete rotation in say 60 seconds, the outside of the circle would be going at a speed of 10cm per minute but inside…

I know we all learn that when we heat a certain volume of air, as in a balloon, the heated volume will be less dense than the surrounding volume of air, so it rises or floats. But I would like to see a layman's explanation of what is really happening at the molecular level. The energized molecules inside the balloon do not move in unison, they are just moving faster. So why do they "float" above the slower, outside molecules? Am I correct that it is a matter of probability, i.e., that an energized molecule would tend to have more interactions (be stopped) moving down towards denser area of slower molecules than it would moving up towards less dense area of molecules, s…

How long does it take gravity to reach an object and exert a pull on it? Meaning: if say there is only one small object with little mass on one side of the universe at the moment, and then suddenly a supermassive object appears on the other side of the universe. These are now the only two objects in this universe. How long before the supermassive object's gravity reaches the small object and begin to pull on it? Or does it happen instantly once the supermassive object exists?

I have a "recycle bag" in my apartment. It's just a huge, heavy bag that I put all my cardboard/paper recycle in. There was a box sitting on top of the bag htat just fell off. The box had to have been sitting there for at least a day and it just decides to fall now? What would cause that?

somebody told me that a decent room fan, eg 40cm one, does not cool air in the room and at first thought this seemed logical and i would've said the same thing, but the question itself made me question it twice. is it really true that a fan does nothing more to air besides putting it in fast motion? I did a quick search on google and I an answer popped up on howstuffworks; http://science.howstuffworks.com/question22.htm They seem to be saying the same thing. But this is what still makes me curious; If we ignore for now that the fan generates heat, let us assume it's just a very efficient fan that doesn't generate considerable amount of heat and all it does is…

hi, this is my first post..i am a 9th grader so don't pounce on me if you find my questions idiotic...i want to learn..anyways,one problem, earth's rotational speed is 493.8m/s..now if i jump from a point on earth's surface so that i stay in air for 1 s..when i land , i should end up 493.8m away from where i started as by the time i reach land ,earth should have moved 493.8m ahead(or behind) me..but i land on the same point from where i started !!!!!!!!!!!! how can this happen as earth will surely move ahead in 1s.... pls explain this...

I'm trying to get the following to make sense - I have 2 vehicles traveling at the same speed. both have 4 wheels. both don't have any special brake assistance. only diff is the weight. Vehicle A = 4x heavier than vehicle B. Now say they both do a full brake lock on all 4 wheels starting at the same line. Will they travel the same distance due to friction or will A travel further? Does momentum play a sizable roll in the dragging distances?

Hey guys, I have to talk for 2 minetus about a runner holding constant speed. Can you guys help me with what say, and i was thinking about makeing a free body diagram, but can someone give me instructions about what forces i should put on there? I could really use help with this, thanks in advance for all help. any terms/ ideas on this is very welcome.

Today in my phisics class my teacher was talking about gravity and he said that noone knows where gravity comes from. Im thinking- isnt gravity a direct relation derived from an objects mass? -why is this such a hard concept then, why cant noone find out where it comes from?

The equation for force is mass times acceleration. Well, the mass of any particular object is constant throughout the universe, just its weight changes, right? According to this logic, lifting things should be just as difficult in space as it should be here on earth, yet astronauts can lift a fridge with their pinky, and not even the one on their writing hand for that matter. What gives? What piece of information am I accidentally ignoring?

Here's an odd phenomenon I can't quite figure out... A microwaveable sausage comes wrapped in an air-tight bag (Similar to a bag of crisps/potato chips) When I heat it in the microwave, the bag contracts around the food, as if a vacuum were being created. The hot sausage comes out shrink-wrapped! How is this possible, since the hot meat should make the available air in the bag expand like a balloon. Microwaves only realy have a noticeable affect on sugar, water and fat molecules, not air, and in any case, the bag should expand as it heats. How can hot air contract? Is the meat absorbing the available air? Could the humble sausage be breaking the law…

I'm sure this has been asked before, but I can't find the answer right now. If you stand on the moon and face the earth, you will feel the attraction of the earth's gravity (as well as the moon's). If you then move towards the earth, the force of attraction will increase until you reach the earth's surface when the force will be 1G. If you then burrow into the earth, the force should increase above 1G because you are closer to the total mass of the earth. If you then continue downwards, at some stage the force will start to decrease because it must tend to zero at the centre because it must then increase in the opposite direction as you ascend the "other side" until…

Hi everyone, im new here but i need some help Ive been asked to find the angle between the gravity and gravitational vectors as a function of latitude where gravity is pointing to the center of the earth and the gravitational vector is the sum of the gravity vector and centripetal vector. Can anyone help? Thanks

Planck units are the standard quantities you get by setting the numerical values of the main physical constants equal to one. |G| = |c| = |hbar| = |k| = |e| = 1 setting the electron charge equal to unity is optional. When Planck described these units in 1899 he didnt bother with that. But it is one way of including electrical units (current, voltage) in the system. Relativists often use a variant where they set the numerical value of 8pi G =1 this gives you different Planck units but it makes many of the basic formulas even cleaner. The Einstein equation, the main equation of gravity, just becomes [math]G_{ab} = T_{ab}[/math] the LHS represents curva…

so heres the deal, i have a project due friday. eek, where i have two eggs, in a device no larger than 10 cm by 10cm, i can use anything but food products, and have to drop it 6 meters down, both have to survive... no cracks. i want to increase the time of impact as much as possible, and increase the SA that hits the ground, it also has to be over 1/2 lb in weight, any ideas?!!!?

Hello, A few times I've been stumbling across this equation on the net, but a quick search through my mechanics books didn't help much. It states that for an object: ds = v * dt + (a * dt^2) / 2 where ds is distance moved, dt is time, v is velocity, and a is acceleration. I haven't been able to make any sense from it, and I haven't been able to make it work in an programs that I tested it in. edit: I take it we all agree that ds = v * dt, and that's pretty much it? (given a constant velocity) michael

In order for a moving bowling ball and a moving Ping-Pong ball to have the same momentum what must happen to the speed of both-balls? And what would happen to the speed not mass.

momentum = mass * velocity and since velocity = acceleration * time then momentum = mass * acceleration * time since force = mass * acceleration and therefore acceleration = force / mass then momentum = mass * (force/mass) * time mass cansels out and momentum = force * time

Draw a diagram with rays and wave fronts of the equations intensity maxima (theta max)=inverse sin(m*lambda/d) m=0,1,2,3.... intensity minima (theta max)=inverse sin((m+0.5)*lambda/d) m=0,1,2,3.... Where d is the distance between the two sources. This is a lab question. I dont know what a wave front or a ray looks like on diagram though, I'm not sure what that means. I would have thought it would be the classic interference graph, with the large maxima in the center and then varies mins and maxs as one gets futher from the center. Yet the mins and maxs are supposed to be drawn seperately, apparently. Any insight into this?

Hi, Where does surface tension can we see in our daily routine? Thanks...