# physics please HELP !

128,227 results, page 27

### college physics

A CD has to rotate under the readout-laser with a constant linear velocity of 1.25 m/s. If the laser is at a position 3.2 cm from the center of the disk, what are the revolutions per minute (rpms) of the disk? Can someone please help me solve this problem step by step. The ...

### physics please help!!

You are lost in the woods with a friend. He's nearsighted and you're farsighted. You decide to start a fire to attract attention. Thankfully, it's a bright sunny day and you're both wearing your glasses. Whose glasses do you use to focus the sun's light to start the fire?

### Physics -- check answers please

I am to fill in the blanks without a word bank, my answers are in brackets. 1. A ____ diffraction pattern is unique because it has a larger central maximum. (single slit) 2. the brightest, clearest diffraction pattern is created with a _____ (barrier)

### Intro Physics - Newton's third rule

a piano mover raises a 1000 N piano at a constant speed using a very light rope in a frictionless pulley system. with what force is the mover pulling down on the rope? Show steps please! Thank you!

### NEED HELP PHYSICS!!!

A person is flying a model airplane with mass 82.2 gram in a horizontal circular path on the end of a string 10.5 m long. The string is horizontal and exerts a force of 3.22 N on the hand of the person holding it. What is the speed (in m/s) of the plane? PLEASE LEAVE FULL ANSWERS

### Physics

A 21 kg child swings on a playground swings 3.6 m long. What is period of her motion? 2) If her older brother, who weighs twice as much as she does, rides in the swing instead, what is the period of the motion? Assume the center of mass to be at the position of the seat in ...

### physics

Consider a block on an incline plane. The coefficients of static and kinetic friction between the block and the incline are µs = 0.353 and µk = 0.31. Calculate the critical angle θc, where the block just begins to slide. Answer in units of ◦. The block weighs 1kg...

### Science, physics

A ship is heading north at 15km/h in a tide moving at 6km/h westward. Determine the magnitude and direction of the resultant velocity of the ship. I can't answer it because I don't get the formula. And please give me the formula. I need the answer later. I'll wait! Thankyou in...

### Physics

Johnny was in a closed door meeting and suddenly his phone rung. His immediate response was to cover his cellphone with his hand and then asked to be excused. Why did he cover his phone with his hand? PS: Please explain it briefly but the thought is very clear and easy to ...

### English

1. Please come to see me in the afternoon, when I will be free. 2. Please come to see me in the afternoon, and I will be free then. 3. Please come to see me in the afternoon, for I will be free then. 4. Please come to see me in the afternoon, and then I will be free. 5. Please...

### Physics

If 2.4 m^3 of a gas initially at STP is compressed to 1.6 m^3 and its temperature raised to 30 degrees C, what is the final pressure? I am having a little problem filling in the blanks...... I know that I need to use the formula P1v1/t1 = p2v2/t2 but I think I am missing ...

### Physics-PLEASE ANSWER, it's due soon!

A copper calorimeter can with mass 0.202 kg contains 0.185 kg of water and 1.40×10^−2 kg of ice in thermal equilibrium at atmospheric pressure. If 0.900 kg of lead at a temperature of 417 degrees celsius is dropped into the can, what is the final temperature of the ...

### Physics

A certain "brand-new" (never-used) 9.0 volt cell contains 40mC of charge. The Electric energy "stored" in the cell amounts to about (___) joules. 0.0 0.06 37.5 .36 60x10^-4 I'm not too sure how to figure this problem out. I initially thought 40/9, but the answer was not one of...

### english

I need a description of a major theme from The Robber Bridegroom by Eudora Welty, please please please. -Preferably the theme with "Jamie Lockhart is the bandit of the woods. And the bandit of the woods is Jamie Lockhart" Thank you!!!

### Physics

My last problem for the day: A) The centers of two 11.00 kg spheres are separated by 0.09 m. What is their gravitational attraction? I got 9.96 x 10^-7 N. B) What is the ratio of this attraction to the weight of one of the spheres (at the surface of the Earth)? I'm sure this ...

### Physics- PLEASE HELP

Assume you are agile enough to run across a horizontal surface at 11.60 m/s on an airless spherical asteroid of uniform density 1.0x103 kg/m3, independently of the value of the gravitational field. To launch yourself into orbit by running, what would be (a) the radius? (b) the...

### PHYSICS - PLEASE HELP

A 1.00 kg pendulum bob is released from a height of 0.200 m. Its speed at the bottom of its swing is 1.95 m/s on the first pass. How much energy is lost due to friction during one complete swing of the pendulum? I get Ep=mgh 0.2*9.8*1 =1.96 then i get Ek=1/2mv^2 1/2*1*1.95^2...

### Physics

Two equal masses(1 and 2) are connected by an ideal rope across a pulley. This system is on a larger block A; 1 is on top of A, while 2 is hanging off the side, and the pulley rests on the corner of A. The question is what is the minimal acceleration of A such that masses 1 ...

### physics help!

A wire of 62cm length and mass 13g is suspended by a pair of flexible leads in a magnetic field of 0.44T. What are the magnitude and direction of the current required to remove the tension in the supporting leads? Please also scroll down because I also have a question not ...

### please i need help accounting

i have a promblem it gives me the information and form i understand the information but cant fill out the form because i don't know how and its 71 points out of the whole exam. is there anyway u can help me out if i give you the information. its about transactions the first i ...

### English Literature

Hello, I'm a English Literature student. I'm going to make a Project on William Shakespeare and John Milton. As I said, it's an English project, So please suggest me some good topics/title for both the projects. Also please give me some general tips and ideas. Please help, its...

### Physics repost please check

Posted by Mary on Monday, November 5, 2007 at 8:21pm. Suppose that the electric field of an electromagnetic wave decreases in magnitude. Does the magnetic field increase, decrease, or remain the same? Account for your answer. For Further Reading Physics - bobpursley, Monday, ...

### Math ; please please help.

1. Explain in detail how to determine the value of the independent variable in a quadratic relation if the value of the dependent variable is known. Please check my answer - You would substitute the value for the dependent variable, then you would solve for the independent ...

### please check (physics)

Current flows out of a 110V source through a 10 ohm resistor and then through parallel branches, one containing a 20 ohm resistor and the other a 30 ohm resistor. Find V I R P V I R P 50 5 10 250 60 3 20 180 60 2 30 120 _____________________________ 110 5 22 550 First R total...

### Physics please help

Calculate the force required to pull a copper ball of radius 3.00 cm upward through a fluid at the constant speed 7.00 cm/s. Take the drag force to be proportional to the speed, with proportionality constant 0.950 kg/s. Ignore the buoyant force.

### physics please help !

A helicopter is ascending vertically with a speed of 5.20m/s . At a height of 110m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [Hint: for the package equals the speed of the helicopter.]

### Physics Help!! I'm so confused!!!

A fire hose sprays 450 liters of water a minute onto a fire with a velocity of 17.0 m/s. Water has a density of 1 kg/liter. What is the average force acting on the fireman holding the hose due to the water? PLEASE EXPLAIN.

### physics

An animal-rescue plane ﬂying due east at 40 m/s drops a bale of hay from an altitude of 73 m . The acceleration due to gravity is 9.81 m/s^2. If the bale of hay weighs 177 N , what is the momentum of the bale the moment it strikes the ground? Please help!

### Physics help please

In an experiment done by scattering 5.5 MeV α particleson a thin gold foil, students find that 10,000 α particles arescattered at an angle greater than 90 degrees. How many α particles will be scattered between 60 degreesand 80 degrees?

### Physics

i41 tinypic com/2qna74k png (add the periods) For the vectors in the figure, with a = 6.4, b = 2.5 and c = 6.87. Calculate a(dot)b calculate a(dot)c calculate b(dot)c I got 0 for a(dot)b but the same method (ac*cos(theta)) does not work for the other two, please help.

### Physics

I posted this earlier and no one responded so I am going to try again. I have to Distinguish between atomic physics and nuclear physics, so here is what i have. which deals with the atom as a system of electron(s) and a nucleus and nuclear phys

### Physics

A railroad flatcar is loaded with crates. The coefficient of static friction between the crates and the floor is 0.27. If the train is moving at 59.7 km/hr, in how short a distance can the train be stopped with a constant acceleration without causing the crates to slide? I've ...

### Physics (Electric fields and Coulomb's Law)

I need help with this question please. An ion harvester is scouring deep space for isolated xenon (Xe+) ions. A xenon ion is singly ionized, and has a charge of +e. If the field meter reads 0.000000202 N/C, how far away is it from the ion? _________ m Thank you

### Physics

A 1.0 x 10^3 kg elevator carries a maximum load of 800.0 kg. A constant frictional force of 4.0 x 10^3 N retards the elevator's motion upward. What minimum power, in kilowatts, must the motor deliver to lift the fully loaded elevator at a constant speed of 3.0 m/s? Please show...

### Physics

Please help!! I know how to work the problem to find velocities, but this one has me stumped! A 2.0kg block slides along a frictionless surface at 1.0m/s . A second block, sliding at a faster 4.4m/s , collides with the first from behind and sticks to it. The final velocity of ...

### Science

Explain why the life cycle and skin of the frog make it a good indicator animal if you want to determine the health of local ecosystems. Please please help. Thanks so much.

### history

describe the efforts between the 1850's and 1870 which resulted in the unification of italy. I have to get it from a book but i cant find any so if you could please give me the citation info to please.

### Algebra 1

I need some help please. I don't understand the math that we are doing. Please explains to me in detail how to do radical expressions and like how to simplify them and stuff. I don't get it and it would be much appreciated

### Science

How can atoms with fewer than 8 valence electrons fill their outermost energy level? (If you can, can you please help me use either sulfur or magnesium to explain the process please?) Thank You!

### Math Help Please

How long will it take for prices in the economy to double at a 6% annual inflation rate? Round to the nearest hundredth. Please explain how to solve this problem, thanks.

### Social Studies

When did France become a country? Please don't just write the late 400's or something similar to that. Please give me the year, month, and date. Thanks!!!!!!!!!!!!!!!!!!!!!!:):):):):):):):):):):):):):):):):):):):):)

### social studies (latitude & longitude)

what is the city and continent name of these : 34° S and 58° W 34° S and 18° E 51° N and 0° 30° N and 31° E 40° N and 2° W 36° N and 4° W °°°° Please please help ! i have been trying to find the answer to these for a long time but i just cant get them. °°°°

### geography (grade 6)

PLEASE HELP!! i posted the question yesterday, they were unable to help me !please help me ! what is the recent environment issue that affected a canadian business that sellls its products internationally.

### math 115

I need help please, Find an equation of the line having the given slope containing the give point m=5/6(5,-8) 5/6+ 40/6 is this correct and if not can you explain to me what I am doing wrong please

### health Ed

please please pleeeeeeeeeeeeeeeeeeeeeeeaaaaaase help! What are the societal influences (economic, education and government policy) that can contribute to a supportive family environment? (Focus on families with adolescents)

### grade5

5 devices of energy in your home. please tell me. whats the largest source of power in the whole toronto. please help me i`m confused. i cant find good websites.

### Math please help!!

Solve the system using substitution. y = -2x + 5 3y = -x - 5 I already got the answer, just wanna make sure it's correct. Please show work as well.

### litreature

please help me , this journal is for tomorow and i can't do it: the idea that power courrupts but suffering can redeem is fairly common plot support this theme, please answer as fast as you can . thank you

### Social Studies 9

PLEASE I NEED THIS BY TOMORROW!!!. why do you think lawyers in land claims trials more then 200 years after it was proclaimed . NO LINKS PLEASE.

### MATHS GEOMETRY!!! URGENT PLEASE.

A triangle has side lengths 10,17 and 21cm. Find the length of the shortest altitude. And please show working out to help me understand.

### polynomials help me please

Im sorry here is the problem rewritten X^3 -2x^3 + 3x-1 : X^2-x+4 I have to get the sum diff and product and it kicking my tail i think i keep doing it wrong can someone please help me

### algebra

(38) please help me figure this out. The multiple choice answers did not match the answer that I got. Select approx values of x that are solutions to f(x)=0 where f(x)=-7x^2 + 5x + 9 please show me steps

### alGEBRA 2 help please would appreciate

find the foci of 9x^2-25y^2=225 I get this far a^2=5 and B^2=3 AND I KNOW I HAVE TO USE THE formula c^2=a^2-b^2 i don't know what to do now if add it i get c^2=34 please help show the step thanks

### Chemistry. Please

If 15ml of 1M sulfuric acid is used until faint pink endpoint is reached how many moles of magnesium hydroxide are in 50ml solution. Please help

### Algebra please help out

In Beijing in 2008, the women's 3,000 meter steeplechase became an Olympic event. What is this distance in kilometers? Please help answer thx

### Science PLEASE HELP

How does Exothermic and Endothermic reactions affect the rate of a reaction? Please help. I need something that will be easy for me to understand and adopt into my own words. Thank You :)

### math help!!!!! Thanks

Find the volume of the cylinder with a radius of 34m and a height of 27m. This is how I did it can you please tell me if I did it correct, thanks. V= 3.14r^2h = 3.14*34^2*27 = 3.14*1156*27 = 98005.68 If this is not it can you please explain what I did wrong?

### English

Please help correct grammar sentence below: 1. Please be informed that starting on Nov.22,2015 rate of internet charge will be pesos 15.00 per hour. thank you.

### SS

How does the geography of Eastern Europe most affect farming in the region? There's more, but please answer this question first. If you know all the answers to the test please tell me them! Thanks!

### matha

Please I am lost on how to find the derivative of function using first principal,could someone please work out an example on how to solve such problem?

### PLEASE HELP!! PHYSICS

A 0.63-kg metal sphere oscillates at the end of a vertical spring. As the spring stretches from 0.13 to 0.22 m (relative to its unstrained length), the speed of the sphere decreases from 5.95 to 4.75 m/s. What is the spring constant of the spring? (The sphere hangs from the ...

### Physics - PLEASE HELP

A rod is 2.40 m long and has a diameter of 2.50 mm. A force of 2000 N is applied to the end to stretch the rod by 1.00 mm. What is the tensile modulus for this rod? 7.50 × 1011 N/m2 8.70 × 1011 N/m2 9.78 × 1011 N/m2 10.2 × 1011 N/m2 10.8 × 1011 N/m2

### physics/orbital speed

an asteroid orbits the sun at a constant distance of 4.44e+11 meters, the suns mass is 1.00*10^30kg, what is the orbital speed of the asteroid? Please explain step by step thanks

### Physics ASAP PLEASE

A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the baseball’s initial velocity is 12.0 meters per second. What is the magnitude of the ball’s initial velocity?

### Physics, Please Help!

A helium-neon laser beam has a wavelength in air of 633 nm. It takes 1.48 ns for the light to travel through 34.0 cm of an unknown liquid. What is the wavelength of the laser beam in the liquid? (answer in ns)

### physics

Can someone please explain to me why or how this statement is true? I don't understand it.. Two events that are simultaneous in one inertial frame of reference will not necessarily be simultaneous in any other inertial frame of reference. Thank you

### physics

A 2.60 kg steel gas can holds 15.0 L of gasoline when full. What is the average density of the full gas can, taking into account the volume occupied by steel as well as by gasoline? Please show the steps, thanks.

### Physics

A 2-hp motor drives a sanding belt. If the efficiency of the motor is 87% and that of the sanding belt 75% due to slippage, what is the overall efficiency of the system? The answer has to be 65.25%. Can someone please help me to work it out?

### PHYSICS HELP PLEASE!

A baseball is thrown at an angle of 40.0° above the horizontal. The horizontal component of the baseball’s initial velocity is 12.0 meters per second. What is the magnitude of the ball’s initial velocity?

### physics

A steel rod of length 1m is heated from 25°c to 75°c keeping its length constant.The longitudinal strain developed in the rod is:(steel:12 X 10^-6/°c) "6X10^-4" ; "-6X10^-4" ; "0" please help me as soon as possible by explain this.

### Physics

What net force F will accelerate a 0.5 kg mass at 4 m/s2? If this same net force were applied to a 20 kg mass, what would its acceleration be? Please show me step by step including the right equations

### Physics

A 5 kg magnet exerts a constant force of 3 N on a 0.25 kg magnet. 1) What force will the smaller magnet exert on the larger magnet? Please show step by step including the right equations for this problem

### Physics

v(subscript)t = g/k, describe the effects that changing the value of k would have on the terminal velocity of the object. v(subscript)t is terminal velocity, k is a constant dependent on the size and shape of the falling object. Help, please.

### Physics, Please help!!!

A car accelerates at a constant rate from zero to 32.6 m/s in 10 seconds and then slows to 14.8 m/s in 5 seconds. What is its average acceleration to the nearest tenth of a m/s2 during the 15 seconds? What was the acceleration during the first 10 seconds in the previous problem?

### physics

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

### Physics

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

### physics

An object is solid throughout. When the object is completely submerged in ethanol alcohol., its apparent weight is 15.2 N. When completely submerged in water, its weight is 13.7 N. What is its volume? Steps please.. answer isnt really necessary

### Physics

(a) Find the speed of a satellite moving around the earth in a circular orbit that has a radius equal to five times the earth's radius of 6.38 106 m. (b) Find the satellite's orbital period. Please Help!

### Physics

An object gets the acceleration 8.0 m/s2 in a vertical direction (y) but 5.0 m/s2 in a horizontal direction (x). What will be the position of the object at the time t=2.0 s if his initial postiotion was (0,0), initial speed in y-direction 0 and in x-direction 5.0 m/s? Given ...

### 5th grade math

yes ,i definetly did,more than once ,i just had trouble comprehending the way they try to explain it.thats why i asked to please get help showing several of both kinds of problems,some addition &some subtraction so i could try to understand how they where done.please help by ...

### Social Studies

PLEASE ANSWER! PLEASE ANSWER! PLEASE ANSWER! 1) Identify two problems resulting from urban sprawl in the western region of the United States. If these problems are not solved, what will the outcome likely be? 2) Why do you think the Canadian government is opposed to Quebec's ...

### physics help please 1!!

A 1.27 kg hoop with a radius of 10.0 cm rolls without slipping and has a linear speed of 1.32 m/s. Find the rotational kinetic energy. Find the total kinetic energy of the hoop.

### Physics

is force and normal force the same thing? if not what is the difference. for instancee if a problem said given a force of 20 newtons. would normal force be 20 newtons? please answer !!!!!!!!!

### Physics

Five Boys are pushing a snowball, and each is pushing with a force of 10.0N. However, each boy is pushing in a different direction. They are pushing north, northeast, east, southeast, and south. (Each boy is pushing at an angle of 45.0 degrees relative to his neighbor.) What ...

### Physics

PLEASE HELP! I'm doing a physics demonstration, and in part of it I'm trying to explain why steel wool burns and normal steel doesn't. I know it's something to do with the smaller surface area and/or mass but I don't know WHY it burns because of this. Can anyone help me? I'm ...

### Physics

A vector changes if 1. its direction changes. 2. Any of these 3. its magnitude changes. 4. its direction and magnitude both change. 5. None of these i know it is not 3 or 4. Please explain it to me

### physics

A pendulum clock that works perfectly on Earth is taken to the Moon. (a)Does it run fast or slow there? (b) if the clock is started at 12:00:00 am, what will it read after one Earth day(24hrs)? Assume that the free-fall acceleration on the Moon is 1.63 m/s^2 I tried to do this...

### physics

Hello can you please help me with this investigation. I am having lots of problems with it can you please help. Thandeka wanted to investigate whether the number of vibrations per second depended on the length of the pendulum string. She sat up the apparatus. She pulled the ...

### Physics plz help

(a) What is the energy of a pendulum (L = 0.9 m, m = 0.4 kg) oscillating with an amplitude of 4.3 cm? (b) The pendulum's energy loss (due to damping) is replaced in a clock by allowing a 2.3-kg mass to drop 1.0 m in 1 week. What percentage of the pendulum's energy is lost ...

### Physics

A spring with a spring constant of 22N/m is initally compressed by 2.3cm. How much work is required to compress the spring an additional 1.7 cm? I can't find information in my book about compression; only work and exertion. Please help and provide all steps for work. Thank you...

### Physics

A pistol is fired horizontally toward a target 120 m away but at the same height. The bullet's velocity is 200 m/s. How long does it take the bullet to get to the target? How far below the target does the bullet hit? please explain why you used the formula and how you got the ...

### Physics

A 1.50x10cube is going up a road inclined at 10degrees. If the coefficient of friction is 0.7. Determine the force that will move the car up the inclined with a constant speed. Given: m=1.50x10cube angle=10degrees coefficient=0.7 Required: F=? PLEASE HELP..

### please help with physics!!

A 0.55-{kg} croquet ball is initially at rest on the grass. When the ball is struck by a mallet, the average force exerted on it is 220 N. If the ball's speed after being struck is 3.2 m/s, how long was the mallet in contact with the ball?

### Physics please help!!

Water is flowing in a straight horizontal pipe of variable cross section. Where the cross-sectional area of the pipe is 3.50·10-2 m2, the pressure is 5.30·105 Pa and the velocity is 0.310 m/s. In a constricted region where the area is 12.90·10-4 m2, what is the velocity?

### physics

A cable lifts a 1220-kg elevator at a constant velocity for a distance of 39.7 m. What is the work done by the tension in the cable? can someone help me with this the answer is supposed to be in joules i tried doing it by 1220(9.81)(39.7) = 475137J but that is not the answer ...

### Physics (vectors)

Please help me with this question about vectors. Thanks. If you are given a graph with a vector starting at the point (1,-1)and the arrow goes to the point (0,-4). What is the vector in rectangular coordinate? I answered (0,-3), but the coordinate for x is wrong and I can't ...

### Physics

Please, help me answer this question. Two balls are moving in the same direction. Ball A has half the mass of ball B, and is moving at twice its speed. (a) Which ball has the greater momentum? (b) Which ball has greater kinetic energy? Thank you

### Physics please help.

A ball of Styrofoam (ρ = 100 kg/m3) is totally submerged in water. The ball has a mass of 300.0 g (it could be a pretty big block). What is the volume of the ball? If a string holds the ball when it’s in the water, what’s the tension in the string?

### physics

If I solved for centripetal acceleration how can you determine the magnitude of the force required to produce this centripetal acceleration? Next step please.... v=15m/s r=35m m=1300 kg 15 squared/35m=225/35= 6.43m/s squared