Physics homework Definition and 292 Threads

Help on Physics Homework?? Some please explain how to get Fnet , F2, and how to find the direction of dp/dt. And the rest of the stuff i got wrong on this homework. anyhelp would be much appreciated.

I have this problem on a web assignment due on the 20th of this month. A few of the problems have completely blown my mind including the following: A force F0 causes an acceleration of 18 m/s2 when it acts on an object of mass m sliding on a frictionless surface. Find the magnitude of the...

Inside the toroid, in which direction does the magnetic field point, if the current is going clockwise around the loop? So I tried to consider the fields due to two points on opposite sides of the toroid. Then I got stuck becuase I don't know what direction their fields added up. What do I do?

Homework Statement a rock is tossed straight up with a speed of 18m/s. when it returns, it fallls into a hole of 12 m deep. a) what is the velocity of the rock as it hit the bottom of the hole? b)how long is the rock in the air, from the instant it is released until it hit the bottom of the...

Homework Statement Your starship, the Aimless Wanderer, lands on the mysterious planet Mongo. As chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 11.0 returns to the ground in 9.00 ; the circumference of Mongo at the equator is...

Homework Statement The rectangular and polar coordinates of a point are (x,y) and (r,theta) where x = 7 and theta = 52 degrees. Determine r and y. Homework Equations r = srt(x^2 + y^2) theta = arctan(y/x) x = rcos(theta) y = rsin(theta) The Attempt at a Solution I tried to...

Homework Statement Joe puts 11400 J of energy to drag crate 25 m across floor with constant speed. Rope makes 48 degree angle with horizontal. Force exerted by the rope on the crate? What is the force of friction acting on the crate to impede its motion? What work is done by the floor...

A circular disk of fixed radius r is used in a humidifier, vertically. It is partially submerged in water and rotates on its center. The goal is to determine the height above the water, h, at which to fix the center so that the exposed wet surface area is maximized. 1. Find the surface area...

Okay, I have stuck on this question for about 10 minutes now, and just thought I would ask you guys for some help. Okay, the question is "A 2229.5 kg car is coasting along a level road at 31.1 m/s. A constant braking force is applied, such that the car is stopped in a distance of 70.2 M. What...

Physics really stumps me, I try to study a lot but its not getting in my head... Anyway here are the questions i need help on. I tried doing the problem out but it confuses me.. SO far I'm going over velocity, displacement, like V=d/t and D=vt t=d/v 1) You drive your Miata from home at an...

Homework Statement Please be advised, i posted these questions on two other forums, so you may check to see if a question you're planning on answering has been addressed. so far, (4.9) has been answered, i will try to keep you up-to-date...

A jet plane lands with a velocity of 101 meters/second and can accelerate at -5.1 meters/second2 when coming to a rest. a) Once it hits the runway, how long till it stops? b) Can this plane land on Gilligan’s Island if its runway is 0.80 x 109 μ meters long? 2. Homework...

Homework Statement Question #1: Δd=v¹Δt+½a(t)² Solve for: a Question #2: E= ½ m * v² Solve for: v Homework Equations Δd=v¹Δt+½a(t)² v = Δd / Δt a = v² - v¹ / Δt v² = v¹ + a * Δt Δd = (v² - v¹) * Δt Δd = v¹ * Δt + ½ a ( Δt )² E= ½ m * v² The Attempt at a...

i do not have a protractor with me and am very new to physics at the college level and have not gotten the book yet do to my student loans not bein processed and released at this time... PLEASE HELP the question on my homework i am having trouble with is as follows go 83.9 paces at 188...

hello..im new to nuclear physics and i have problems attempting helf life questions.. hope you can help me with this question.. The half-life of a given radioactive isotope is 10 years. What is the mass of this isotope remaining undecayed after 20 years if the original mass was 12g? thank you..

a disk and ring have the same mass, radii, and velocities.if they both go up an incline, how will the distances that the objects move up before coming to rest compare? which one reaches the top first and why? help me understand.

I am having trouble understanding how to work this 3 part problem. A 9 kg mass slides to the right on a surface having a coefficient of friction 0.34. The mass has a speed of 4 m/s when contact is made with a spring that has a spring constant 159 N/m. the mass comes to rest after the...

Homework Statement The rear window in a car is approximately a rectangle, 1.3 m wide and 0.30 m high. The inside rear-view mirror is 0.61 m from the driver's eyes, and 1.37 m from the rear window. What are the minimum dimensions for the rear-view mirror if the driver is to be able to see the...

Homework Statement "If Ganymede, one of Jupiter's moons, has a pariod of 7.15 days, how many uits are there in it's orbital radius? Use the information given in Example Problem 1." Example Problem: "Galileo measured the orbital sizes of Jupiter's moons using the diameter of Jupiter as a...

Homework Statement A merry-go-round in a playground has a radius of about 2 m and a mass of about 400 kg. Starting from rest, a parent begins to rotate it with constant angular acceleration. After 5 s, it reaches its final angular velocity of about pi/2 rad/s, and continues to rotate at that...

Homework Statement See link. http://img515.imageshack.us/img515/6383/picture15lj9.jpg Homework Equations Imp = integral F dt mv = momentum mgh 1/2 mv^2 The Attempt at a Solution I drew to FBD's to find the impulses and such, but I just don't know what to do. I then tried...

Homework Statement A stunt man drives a car at a speed of 19.3 m/s off a 32.8 m high cliff. The road leading to the cliff is inclined upward at an angle of 19.3°. How far from the base of the cliff does the car land? What is the car's impact speed? What is the angle of impact...

Hey! I have been trying this problem forever and can't seem to figure out the answer for y. I thought that I was supposed to take sin(41)*65?? But that answer keeps coming up as wrong?? Any help would be amazing! A particle undergoes a displacement of magnitude 65 m in a direction 41°...

Two cars, A and B, are traveling in the same direction, although car A is 208 m behind car B. The speed of A is 25.7 m/s, and the speed of B is 18.6 m/s. How much time does it take for A to catch B? Time it takes for A to catch B is speed=distance/time time=distance/speed =208/25.7...

Hi ^^! I was doing my physics homework and had a little trouble doing this one, so I was wondering if anyone could help me out if they had time. It would mean alot, but thanks anyway just for reading this ^_^! I appreciate it =) Homework Statement Two spheres, each having a mass of 50 mg...

I can't figure this problem out and i don't know where to start. A young boy(50kg) wants to lift a boulder with a mass of 2500kg. He can wedge a board under it so that from the boulder to a pivot/fulcrum is 0.6 meters. How long does the other end of the board have to be for the boy to lift...

This is driving me crazy. I need to make sure I'm reading my physics homework correctly. Alright, a uniform, solid ball is pushed with initial velocity V(0) so that it slides. As the ball moves, kenetic friction between the ball and the surface it is traveling on causes the ball to rotate...

http://img76.imageshack.us/img76/6271/pichp1.gif A bobsled run leads down a hill as sketched in the figure above. Between points A and D, friction is negligible. Between points D and E at the end of the run, the coefficient of kinetic friction is µk = 0.4. The mass of the bobsled with...

Absolutely Basic Physics Homework HELP! Hello there! I'm a new member and I have come across to site using google for some basic help on my physics homework!(I have just recenty started physics AP, every bit of material is new to me.) It would be extremely helpful to me if you can also help me...

We just started vectors today and introduced the I and J axes. He insists we use I and J instead of X and Y, that's okay. So basically here is the question asked: A person riding a bike has a velocity v=32m/s I + 12m/s J. Determine the magnitude of hte velocity and hte bikes direction...

Hi, I have just started AS Physics and I am doing mechanics at the moment. I am stuck on a question at the moment which I would like to know if someone can answer: A stone is dropped from rest from a diving board which is 6 metres above the water surface of the pool below. After it hits...

I need help with physics...I don't want answers...that's for cheaters, and can retrieve the answers...I need help understand how the answer came to be. The book I'm using is giancoli, I'm on chapter 16 Electric Charge and Electric Field.:eek: I have a square with both + and - charges of 6.00mC...

I have been having trouble with this one problem... If you could supply me with an answer and possibly a brief description of your methods I would be infinately in your debt: A bus travels 320 km south along a straight path with an average velocity of 96 km/h to the south. The bus stops for...

This question, from a previous A.P physics exam, was given as a homework problem. I am wondering if anybody could tell me if I am on the right track or totally wrong. Three blocks of masses 1.0, 2.0, and 4.0 kilograms are connected by mass less strings, one of which passes over a...

so here i am doing my physics homework. everythings fine, but then i get this whopper of a problem, which is for major marks, and i can't seem to solve it for some reason. here she is: a ramp is setup on the edge of a table a ball slides down this ramp and picks up speed. just as...

A simple pendulum is made from a 0.60 m long string and a small ball attached to its free end. The ball is pulled to one side through a small angle and then released from rest. After the ball is released, how much time elapses before it attains its greatest speed? So would the max speed be...

I was wondering about the following problem: You are looking down on a single coil in a constant magnetic field B = 0.9 T which points directly into of the screen. The dimensions of the coil go from a = 6 cm and b = 15 cm, to a* = 20 cm and b* = 19 cm in t=0.028 seconds. If the coil has...

Ok i thought i had this under control, but now i come to think about it, i get more confused. I know d sigma/d U for any system must be positive because the temperature must be positive (sigma is the entropy and U is the energy). But what about this? Consider the model of the paramagnetic system...

Hey a friend asked me for help on his physics homework, and I found this place and was wondering if you guys could help me out. 2: In 1772, the famed Italian-French mathematician Joseph Louis Lagrange was working on the infamous three-body problem when he discovered an intersting quirk in the...

As a hobby, you like to participate in reenactments of Civil War battles. Civil War cannons were muzzle loeaded, meaning that the gunpowder and the cannonball were inserted into the output end of the muzzle, then tamped into place with a long plunger. To recreate the authenticity of...

A radioactive nucelus (cobalt - 60, has 27 p+'s and 33 e-'s) emits a photon (gamma ray) of wavelength 2.7 x 10^-13 m. Assuming the nucleus was intially at rest, what si its recoil velocity upon emitting this photon? I have already figured out the momentum using this information. When I...

Two speakers produce a 180Hz sound in phase. If an intensity is located 2.10m from the nearer spearker, find the distance to the further speaker if the speed of sound in the air is 345m/s. I don't understand exactly what this problem is asking for, and I can't find an equation relating these...

In this problem you will estimate the heat lost by a typical house, assuming that the temperature inside is 20 degrees and the temperature outside is 0 degress . The walls and uppermost ceiling of a typical house are supported by 2*6-inch wooden beams with fiberglass insulation in between. The...

I'm having trouble solving this one: Two motorcycles are traveling in opposite directions at the same speed, when one of the cyclists blasts her horn, which has a frequency of 544 Hz. The other cyclist hears the frequency as 563 Hz. If the speed of sound in air is 344 m/s, what is the speed...

A 2.0 kg mass slides down a frictionless inclined plane that makes an angle of 30 degrees with the horizontal. The sass starts from rest. What is its speed after it has slid a distance of 3.0 m along the incline? I got: F = (sin30)(9.8) F = 4.9 N W = Fd W = (4.9) (3) = 14.7 J W =...

Pepe, the clown, is jumping on a trampoline as Babette, the tightrope walker, above him suddenly loses her balance and falls off the tightrope straight toward Pepe. Pepe has just started upward at 15.0 m/s when Babette begins to fall. Pepe catches her in midair after 10.0s. a) How far has...

I think someone may have previously asked for help on a problem similar to this one: There are three blocks connected by a string. m1 is 0.5kg, m2 is 1.7kg. m1, and m2 are connected at the top of a surface and m3=2.9kg, is hanging of the end of a pulley. looks kinda like this: [ m1 ]----[...

I've been having some problems with these problems, I'd appreciate any help. 1. There are 2 people standing on a roof 80 m high, person #1 throws a ball straight up in the air with an initial velocity of 20 m/s, person #2 has a replica of the ball and drops it off the roof at the same...

New to physics, and I'm a little confused on one problem on my homework: 1) A runner runs 5.0km along the course east, then turns around and runs 5.0km west along the same path. She returns to the starting point in 40 min. What is her average speed and velocity? The speed was easy to...

i need help with this problem. I've tried for a while now and it is driving me crazy! I've tried about everything including using what little calculus i remember from last year! please help! the problem is: you are standing on a cliff and you drop a rock straight down, neglecting air resistance...