physics please HELP !

129,474 results, page 49


A certain kind of glass with index of refraction of 1.65 for blue light of wavelength 430nm and index of refraction 1.615 for red light with wavelength 680nm. If a beam of light containing these two colors has incident angle of 30 degrees what is the angle inside the glass? I ...


I'm haivng troulbe proving the deriviation of this formula on my own... could you please help me derive the proof of the formula or maybe show me one thansk... I need to prove this formula period of a mass spring system in simple harmonic motion T = 2 pi square root of (m/k) ...


1.) A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed 2.5 cm in bringing the block to a ...


1.) A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed 2.5 cm in bringing the block to a ...

PHYSICS help please!!!!!!!!!!

At a nuclear power plant water at 8°c from a lake is used in a heat exchanger to condense spent steam at a temperature of 120°c,to water at 85°c before it is recycled to the reactor. If the cooling water returns to the lake at a temperature of 19°c,how many kilogram of ...

11th grade physics

is there physics in football


physics behind fibre optics


How physics relate on building snowman

As Physics

What does oath will be parabolic mean in physics?


i need someone's help What do you need help with? Please put your question on the board and someone will be more than please to help. thanks for asking Jiskha.

English read my paper please

I have done the paper. can you please read if for me. How can i close it? i need a ending paragraph.

Pre calc

Someone please help me prove these A) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you

Pre calc

Someone please help me prove these A) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you


Can someone please give me ideas of 3 pros of eating meat and 3 cons of eating meat? Please and thank you

math graphing the y-intercept

y=2over3=1 dont know how 2 solve it 2 get the y-intercept dont know how 2 graph it please help and explain it please


How do you spell Narrativeter is this is how you spell it please reply the other one about the english thing please Thank You

Math Symbols



this is a math riddle that i can't do so please help i am a fraction eguivalent to 2/4 the sum of my numerator and my denominator is 21 what fraction am i here it is help me please's


Hi, please help me .i don't have how to prepare that science to make to prepare that project.can u please suggest me.

Science 8R - Ms. Sue Please Help!!!!

Homework - Draw a picture of an atom is there any pictures of an atom I can easily draw, please help

math-please help,need quickly

loga(x-5)-loga(x+9)=loga(x-7)-loga(x+9) all the a's are lower please show work


please show me how to solve this (2x - 5y) power of 2 i am having a problem with the way to step by step please solve this

Algebra-help please

Please help me graph this Absolute value x+1 inside absolute brackets -3<4 Where would this be on a graph line?

Algebra help ASAP please

simplify each expression. 1. 6/2b - 1 minus 4/b - 1 2. n-6/2n + 2 plus 4n/3 3. 4/6x^3 - 12x^2 minus x - 3/6x^3 - 12x^2 please explain how to do these!! thanks

delete post please

Please delete my post Posted by Marie on Thursday, January 29, 2015 at 3:59pm.

Math help please

Please help I'm failing Which of the following is a rational number Pie Square root 3 Square root 2 1.3*****

math please help

Solve. 3 ​|4x−3​|−3=8 I keep getting the wrong answer please help me


What are at least two different ways you can ask what you or someone is like in Spanish?(4 points) Can someone please help me please?


1. May I speak to Tom, please? 2. May I speak with Tom, please? ------------------------------- Can we us both 'to' and 'with' in a telephone conversation? Are they interchangable? The same?

physics rotations-please help

Two masses, mA = 35.0 kg and mB = 42.0 kg, are connected by a rope that hangs over a pulley (as in the figure). The pulley is a uniform cylinder of radius 0.50 m and mass 4.8 kg. Initially mA is on the ground and mB rests 2.5 m above the ground. If the system is released, use ...

Physics(Please respond)

1)A 1180-kg van, stopped at a traffic light, is hit directly in the rear by a 753-kg car traveling with a velocity of +1.81 m/s. Assume that the transmission of the van is in neutral, the brakes are not being applied, and the collision is elastic. What is the final velocity of...


Hi! could anyone help me to solve this problem please. Thank you. Question:An electron has a speed of 0.68 c. (a) Find the speed of a proton that has the same kinetic energy as the electron. (b) Find the speed of a proton that has the same momentum as the electron.

algebra 3-4

im in a cal class but were reviewing algebra stuff now. and i have 1 more questions. it says. express the given quantity as a single loragithms 2ln4-ln2 so is it 2ln(2) please tell me if im getting the right answers and if im not then please show me how to do it. thank you for...


Hi - I'm finding this question a bit tricky and think I answered it wrong, can someone please verify for me? Many thanks.... In ƒ¢ EFG, find the value of f, if e = 7.3 cm, g = 8.7 cm and ÚE = 73‹. my answer was 4.73 cm but I'm not confident that I correctly found ...


Please please help this is the second time I have posted this question. Calculate the amount of work it will take to lift a lawn mower with a mass of 8kg onto the back of a truck which is 0.75m off the all conversions in your work.

Socials please someone help me

CAN ANYONE HELP ME PLEASE What were the daily tasks, political views, social life, and economic status like for each of the following in 1820 in upper Canada: Tenant farmer upper-class/clergy British government officials aboriginal peoples

@ Online Students

A student recently posted this. Please heed. "quick backstory; i've been cheating on all of my work except portfolios this whole year cause i'm in online school. but i'm wanting to learn since there's gonna be ACT test in REAL so... please help me on how to do this!"


135.2 J of heat energy are transferred to 24.75 g of mercury. By how much does the temperature increase? (in K) Specific heat of the mercury is 140 J/kg·°C. How much heat is needed to raise the temperature of 24.75 g of water by the same amount? Specific heat of the water is...


  Block A and block B are forced together, compress- ing a spring (with spring constant k = 2500. N/m) between them 3.00 cm from its equilibrium length. The spring, which has negligible mass, is not fastened to either block and drops to the surface after it has expanded...


Two equal-mass stars orbit their centre of mass. The distance between the stars (measured from the centre of mass of each) is 1 AU. What is the period of revolution in years? How much energy would be required to unbind these stars if they each have the same mass as the sun? ...

Physics(Please check)

A paperweight, when weighed in air, has a weight of W = 6.95 N. When completely immersed in water, however, it has a weight of Win water = 4.26 N. Find the volume of the paperweight. Would I multiply the two values of weight and then by the density of water? 4.26=weightinair-...


A weight is hung by a cord from the ceiling of an elevator. From the following conditions, choose the one in which the tension of the cord would be the greatest...least?(draw force diagrams) a) elevator descending at a decreasing spped b)elevator at rest c)elevator rising at ...

Physics HELP!

An ant and a beetle are riding a spinning record on a record player. The ant stands on the outside edge of the record while the beetle stands on the record's label. The ant is four times as far from the center of rotation as the beetle. What is the ratio of the ant's ...


A child pushes a merry-go-round with a force of 80.0 N at an angle tangent to the circle (that is, perpendicular to a radius). If the child pushes it through exactly one full circle, and the merry-go-round has a radius of 1.15 m, how much work does she do? If you could please ...


(Someone please help me !! I don't understand this.) Two tiny conducting spheres are identical and carry charges of -27.3C and +61.0C. They are separated by a distance of 2.64 cm. (a) What is the magnitude of the force that each sphere experiences? (b) The spheres are brought ...

physics - please help

A golf ball of mass 0.045 kg is hit off the tee at a speed of 48 m/s. The golf club was in contact with the ball for 5.4 10-3 s. (a) Find the magnitude of the impulse imparted to the golf ball. (b) Find the magnitude of the average force exerted on the ball by the golf club.

physics help!

A tire is filled with air at 17 degreees C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 39 degrees C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained? Please help step by step!


The problem goes like this... You are pushing a shopping cart at a constant speed. The handle makes an angle of 30.0 degrees with the horizontal and the friction in the cart has a coefficient of 0.400 to account for all the axles, etc. The mass of the cart is 45.0-kg and we ...


Driving in your car with a constant speed of v = 11.7 m/s, you encounter a bump in the road that has a circular cross section, as indicated in the figure below. If the radius of curvature of the bump is r = 34.4 m, calculate the apparent weight of a 65.9 kg person in your car ...


The gravitational force exerted on a baseball is 2.28 N down. A pitcher throws the ball horizontally with velocity 12.0 m/s by uniformly accelerating it along a straight horizontal line for a time interval of 177 ms. The ball starts from rest. (a) Through what distance does it...


A car travelling at 25 m/s slams its break leaving skids marks along a distance 125 m as it comes to rest. the coefficient f friction between the tire and the road is a 5 b 2.5 c 1 2 .4 e .25 A 500N worker pulling a 500 N crate on a rope with a force of 50 N at a constant ...

Physics HELP!

A mountaineer estimates the depth of a crevasse by dropping a stone and listening for sound when the stone hits the bottom. The speed of sound in air is 340m/s. If the sound is heard 10s after the stone is dropped, what is the depth of the crevasse? Do you find velocity first...

Physics help please!

The three 500 g masses in the daigram are connected by massless, rigid rods to form a triangle. What is the triangle's rotational energy (in J) if it rotates at 1.50 rev/s about an axis through the center? (Diagram shows equilateral triangle with 500g masses at each point, the...

lang. arta

read the following question: Brian,would you please take that binder to Mrs.Smith with the red cover? What is the best way to correct the misplaced modifier in the above sentence? A. Brian,would you please take that binder with the red cover to Mrs.Smith? B.Brian would you ...


A school has 63 students studying Physics, Chemistry and Biology. 33 study Physics, 25 Chemistry and 26 Biology. 10 study Physics and Chemistry, 9 study Biology and Chemistry while 8 study both Physics and Biology. Equal numbers study all three subjects as those who learn none...


(a)How much work is done by the field in moving the electron through a distance of 7 cm? J (b) Through what potential difference will it have passed after moving through this distance? V (c) How fast will the electron be moving after it has traveled this distance? m/s


The length of a simple pendulum is 0.79m and the mass of the particle at the end of the cable is 0.24 kg. The pendulum is pulled away from its equilibrium position by an angle of 8.5 degrees and released from rest. Assume that friction can be neglected and that the resulting ...


A small metal ball with a mass of m = 82.5 g is attached to a string of length l = 1.72 m. It is held at an angle of θ = 58.5° with respect to the vertical. The ball is then released. When the rope is vertical, the ball collides head-on and perfectly elastically with an ...

Physics Eletric fields and coulomb's law)

Please, I need the development and correct answer for this problem. I would really appreciate it. 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 ...


Light travels in a line of optical fiber by total internal reflection between a core of refractive index 1.48 and a cladding 1.46 refractive index. The critical angle for total internal reflection to occur inside the core of the fiber is ... 80.6º 48.8º 43.2º 42.5º 24.4º ...


A 82 kg adult sits at one end of a 8.6 m long board. His 23 kg child sits on the other end. Where should the pivot be placed so that the board is balanced, ignoring the board's mass? Find the pivot point if the board is uniform and has a mass of 15 kg. Please help with step-by...

Physics(please check)

A 53-N crate is suspended from the left end of a plank. The plank weighs 21 N, but it is not uniform, so its center of gravity does not lie halfway between the two ends. The system is balanced by a support that is 0.30 m from the left end of the plank. How far to the right of ...

physics- please !

A 3.0kg- block sits on top of a 5.0kg block which is on a horizontal surface. The 5.0-kg block is pulled to the right with a force as shown in the figure . The coefficient of static friction between all surfaces is 0.65 and the kinetic coefficient is 0.42. PART A: What is the ...

physics- please !

A 3.0kg- block sits on top of a 5.0kg block which is on a horizontal surface. The 5.0-kg block is pulled to the right with a force as shown in the figure . The coefficient of static friction between all surfaces is 0.65 and the kinetic coefficient is 0.42. PART A: What is the ...


Galileo's first telescope used a convex objective lens with a focal length f = 1.65 m and a concave eyepiece. When this telescope is focused on an infinitely distant object, and produces an infinitely distant image, its angular magnification is +3.11. What is the focal length ...


Orders of magnitude 4: Assume again a Rubidium atom (mass m=87⋅u) is initially at rest. Again it then absorbs a photon of wavelength λ=780 nm. What is the kinetic energy Ekin of the atom after this process? Please give the energy in μK⋅kB units. This is ...


ok im doing my physics homework and we have to submit the answers online. i keep getting these questions wrong and i only have one more try can someone please tell me how to work it? a 2.5 kg otter starts from rest at the top of a muddy incline 94.6 cm long and slides down to ...


hi- I have a problem I can't seem to get right. here it is. "A retired bank president can easily read the fine print of the financial pages when the news paper is held no close than arm's length, 66.4 cm from the eye. What should be the focal length of an eyeglass lens that ...

Physics- Elena please help!

A 20.0 g bullet is fired horizontally into a 85 g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 156 N/m. The bullet becomes embedded in the block. The bullet block system compresses the spring by a ...


A paralle plate air capacitor has a capacitance of 500.0 pF and a charge of magnitude 0.200 uC on each plate. The plates are 0.6 mm apart. (a) What is the potenetial difference between the plates? (b) What is the area of each plate? (c) What is the electric field magnitude ... please!

I fire a tennis ball from an air cannon, straight up from ground level, at initial speed v0. At the instant it reaches the top of its trajectory, I fire a second tennis ball at the same initial speed. Air resistance is negligible. At what fraction of the maximum height reached...


Tarzan (m = 78.4 kg) tries to cross a river by swinging from a vine. The vine is 10 m long. Tarzan doesn't know that the vine has a breaking strength of 1045 N. What maximum speed (in m/s) can Tarzan have at the bottom of the swing (as he just clears the water) in order to ...

Physics Check My Work Please

Determine the minimum angle at which a roadbed should be banked so that a car traveling at 20 m/s can safely negotiate the curve if the radius of the curve is 200m. * Data: v=20 m/s r=200m *Formula TAN(theta)=v^2/rg *Solution TAN(theta)=(20 m/s)^2/(200m)(9.8 m/s^2) TAN(theta...


A pushes with force of 300 N at 25 degrees. B pushes with force of 275 N at 160 degrees. C pushes with force of 325 N at 300 degrees. Find resultant force. I got 187 N at -19 degrees or 161 degrees. Correct? or could you explain more please? Thank you.

physics as

the figure below shows the graph of force,F (y axis)acting on a trolley of 0.4kg against time,t (x axis) 20--------- ........._-- ........._...-- ........._....--- ........._......--- ........._.......----- 0........5............9 The velocity of the trolley is constant ...


Packing material made of pieces of foamed polystyrene can easily become charged and stick to each other. Given that the density of this material is about 35 kg/m^3, estimate how much charge might be on a 2.5 cm diameter foamed polystyrene sphere, assuming the electric force ...


Apparently, this website cannot display photos, so I'm gonna type my question: A railway truck of mass 8340kg traveling at 14.3ms-1 collides with another truck of mass 6420kg traveling at 8.78ms-1 in the same direction. 1. If after collision the two trucks become joined ...

Physics please help

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)


Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)


A student is thrown in a lake by his teacher, the student has a mass of 70 kg and a volume of 80,000 cm^3. Would the student sink or float? What is the net force on the student? What is the density of an object that has a mass of 2000 kg and a volume of 1.5 m^3? Would it sink ...

Sorry- Chemistry / Ionic Bonding

Hello My exams are coming I'm a straight A student .. the problem however is : My textbooks , teacher and every piece of work that he gives us is complicated can someone explain me how Ionic Bonding works . Please I really beg you... I need your help! My teacher sucks in ...


the population of a country is 65 millions if it grows exponentially in a rate of 1.5% annual 1.-calculate the estimate population in 12 years 2.-when the population increases 4 times could somebody please explain me this kind of problems where you need to use the log and ...

Ms, Sue please respond

I had posted a serious letter of a real situation that happenned. I sm trying to write this letter for that reason. I am not sure where it will seem like an excuse if i bring the forms. please suggest a better way of writing the letter.


sums and differences of rational algebraic expression answer the following perform the indicated operation reduce answers to lowest term 2x/x^2-2x-15 - x-2/3x^2+9 another is t/2rs^2 - 2r/3rst + 3s/30r^2t another is 3x/2x-3 - 2x/2x+3 + 3/4x^2-9 please answer this i need it ...


What is the smallest possible value for the angular momentum L of an electron in the n=5 shell? Lmin= 0 kg*m^2/s What is the largest possible value for the angular momentum L of an electron in the n=5 shell? What is the Lmax? Please help I don't get this.Thank you!


two binary stars moving in a perfect circle orbit The stars have the same mass, the distance between them is one billion km (1x10^9 km), and the time each takes for one orbit is 10.4 Earth years. Determine the mass of each star (m1=m2). (this problem DOESN'T uses the gravity ...


Hi everybody! I need this quick answer, please help! The beam AB in the figure has length 3L and uniform section stiffness EI. The beam is fixed at A(x=0) and loaded by an upward concentrated force, P, applied at its free end B(x=3L). A concentrated moment Q is also applied, ...

Physics, still don't get it!

Suppose a monatomic ideal gas is contained within a vertical cylinder that is fitted with a movable piston. The piston is frictionless and has a negligible mass. The area of the piston is 3.06 10-2 m2, and the pressure outside the cylinder is 1.02 105 Pa. Heat (2109 J) is ...

Physics - electricity

An incandescent lamp is marked '120v,75W' a)what is the current in the lamp under normal condition of operation? b)How much does it cost per hour to operate the lamp if the price of electrical energy is $6.00 per unit? Please stop posting under different names. Use ohms law, ...


A stone is observed falling past a small window 1 meter tall in 0.2 seconds. how fast is it moving as it passes the bottom of the window?how far is the bottom of the window from the roof, where the stone originally began its fall from rest?what is the stone's average speed as ...

Nuclear physics

1) An old wooden tool is found to contain only 11.9 percent of 14C that a sample of fresh wood would. How many years old is the tool? 2) A specimen taken from the wrappings of a mummy contains 7.02 g of carbon and has an activity of 1.34 Bq. How old is the mummy? Determine its...

Physics( Checking answer)

Sorry for re-posting but I really need to know if I did it right. Please someone help! Two 3.0g bullets are fired with speeds of 40.0 m/s and 80.0 m/s respectively. What are their kinetic energies? Which bullet has more kinetic energy? What is the ratio of their kinetic ...


A dinner plate drops and breaks. This best illustrates the ______ law of THERMODYNAMICS A. 1st b. 2nd c. 3rd d. 4th I am inclined to say the 1st because energy can be neither created nor destroyed, it can only change forms. Thus the plate falling lost it's energy as a whole, ...


A small spherical insulator of mass 8.96 10-2 kg and charge +0.600 μC is hung by a thread of negligible mass. A charge of −0.900 μC is held 0.150 m away from the sphere and directly to the right of it, so the thread makes an angle θ with the vertical (see ...

Subject-verb agreement

which of the following sentences demonstrates proper subject-verb agreement? A. News travel fast. B. Measles usually spread through respiratory fluids. C. Physics is a difficult subject to learn. D. They study of various sciences are compelling. A and D are not correct. C is ...


A bar 4.0 m long weighs 400. N. Its center of gravity is 1.5 m from one end. A weight of 300. N is attached at the heavy end and a weight of 500. N is attached at the light end. What are the magnitude, direction, and point of application of the force needed to achieve ...


A mover finds that a 20 kg crate initially at rest requires a 75 N horizontal force to set the crate in motion, but only a 60 N force to maintain a constant velocity. Find a) the co-efficient of static friction between crate and floor. b) the co-efficient of kinetic friction ...

critical thinking

how do assumptions relate to the process of critical thinking? Please note that we don't do students' homework for them. Once you have come up with a response to these questions, please re-post and let us know what you think. Then someone here will be happy to critique your ...

writing/history-QUICK PLEASE

Hi, I'm trying to write a good lead for my research paper on Confucius. I'm using the "snapshot" method. So, I need an important event in Confucius' life that I can describe in writing. PLEASE HELP!!!! THANKS IN ADVAVCE! -aShLeY

Please Help:-(

I really need someone to look at my previous posts and edit them if they need to be edited. Please point out any grammatical errors. Thank you very much. You will find my posts as soon as you enter my name in the Search Box.


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