# physics please HELP !

128,227 results, page 26

### physics

A 45 g superball traveling at 28.0 m/s bounces off a brick wall and rebounds at 24.5 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.60 ms, what is the magnitude of the average acceleration of the ball during this time interval? (Note...

### PHYSICS need help now!!!!!!!!!Please

In a railroad switchyard, a 48ton freight car is sent at 6.8mi/hr toward a 28ton car that is moving in the same direction at 3.8mi/hr .What is the speed of the pair after they couple together?What fraction of the initial kinetic energy was lost in the collision?

### Physics

To combat wasteful habits, we often speak of “conserving energy,” by which we mean turning off lights, heating or cooling systems, and hot water when not being used. In this chapter, we also speak of “energy conservation.” Distinguish between these two usages. Please ...

### Physics help

A blacksmith at a historical reenactment is making an iron hinge. after placing the iron (0.750 kg) in the fire and shaping it with his hammer it is still at 200 C. he puts the iron piece in an 8 L bucket of water at 25 C. what is the final temp. of the iron (assume it is in ...

### physics

A 25 kg cannon ball is fired from a cannon with muzzle speed of 1520 m/s at an angle of 35.5 ◦ with the horizontal. The acceleration of gravity is 9.8 m/s 2 . Use conservation of mechanical energy to find the maximum height reached by first ball. Answer in units of m. I ...

### Physics

"a vector r has a magnitude of 18 units and makes a 30 degree angle with respect to the x axis. find the vector components of r using a protractor and some graph paper to verify your answer by drawing r and measuring the length of the lines representing its components." please...

### physics

A particle moving in simple harmonic motion passes through the equilibrium point (x=0) 9 times per second. At t=0t=0 its velocity at x=−0.01 m is negative. It travels 0.4 m in a complete cycle. The particle's position as a function of time is described by the following ...

### Physics

A 11 kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 2.4 m/s2, find the force exerted by the rope on the bucket of water. I thought I was supposed to use F = M x A for this one, but I keep getting the answer wrong. Help please?

### Physics Please Help

A horizontal spring with k = 70 N/m has one end attached to a wall and the other end free. An 95 g wad of putty is thrown horizontally at 3.4 m/s directly toward the free end. Find the maximum spring compression.

### Physics

25) A 75-g ice cube at 0 C is placed in 825g of water at 25 C. a) What is the final temperature of the mixture? b) If the final temperature is 0 C, then how much ice remains? c) change the ice's mass to 300g, and repeat the problem I don't know how to work this at all!!! ...

### Physics

Can someone please help me? The brakes of a truck cause it to slow down by applying a retarding force of 2.60 103 N to the truck over a distance of 930 m. What is the magnitude of the work done by this force on the truck? Is the work positive or negative? Explain Why?

### Physics

PLEASE ANSWER ASAP!!!!!!!!!! step by step a) find the acceleration experienced by the driver of a car traveling at 50km/h if the car hits a pole and crumples 50cm. b) repeat part a) for a car traveling 100km/h

### Physics

PLEASE ANSWER ASAP!!!!!!!!!! step by step a) find the acceleration experienced by the driver of a car traveling at 50km/h if the car hits a pole and crumples 50cm. b) repeat part a) for a car traveling 100km/h

### maths/physics

PLEASE HELP! A POINT SOURCE OF LIGHT IS PLACED 50 CM ABOVE A CIRCULAR CARD OF DIAMETER 5CM, THE SOURCE BEING DIRECTLY ABOVE THE CENTRE OF THE CARD. WHAT IS THE AREA OF THE SHADOW ON THE FLOOR 70 CM BELOW THE CARD?

### physics-please help

A child of height 1.2 metres stands 3 metres from the foot of a lamp post of height 2.8 metres, at the top of which there is a small source which can be considered as a point. What is the length of the shadow cast by the child upon the ground?

### maths/physics

PLEASE HELP! A POINT SOURCE OF LIGHT IS PLACED 50 CM ABOVE A CIRCULAR CARD OF DIAMETER 5CM, THE SOURCE BEING DIRECTLY ABOVE THE CENTRE OF THE CARD. WHAT IS THE AREA OF THE SHADOW ON THE FLOOR 70 CM BELOW THE CARD?

### Physics, Please Help

A 2130-kg space station orbits Earth at an altitude of 455 km. Find the magnitude of the force with which the space station attracts Earth. The mass and mean radius of Earth are 5.98 × 1024 kg and 6370 km, respectively.

### physics

A hydraulic jack has an input piston with a diameter of 1.00 cm, and an output piston with a diameter of 6.00 cm. What weight (in N) can be lifted when a force of 45.8 N is applied to the input piston? Answer is 1650 N but I need someone walk me through the steps please.

### Physics

You are standing on a 50m cliff and throw a ball upwards at 8.2m/s - calculate the maximum height the ball will reach - calculate the time it will take the ball to return where it started - calculate the speed of the ball when it hits the ground. Please help

### Physics

A mass (0.5 kg) and spring (k = 250 N/m) system oscillates with an amplitude of 3.5 cm. a) What is the total mechanical energy of the system? b) What is the maximum speed of the mass? c) What is the maximum acceleration of the mass? I need help please. What equation should I ...

### Physics ~really need help!~

1) A 1 kg mass moving at 1 m/s has a totally inelastic collision with a 0.7 kg mass. What is the speed of the resulting combined mass after the collision? 2) A cart of mass 1 kg moving at a speed of 0.5 m/s collides elastically with a cart of mass kg at rest. The speed of the ...

### Math

How do I express these in scientific notation AND Log10 form? 1) ln(8.1) 2) 32.8 x 10^-2 + 3.15 x 10^-1 3) 10^-2 x 10^4.5 4) 10^-45 5) 8^2.34 Please show some effort, and please stop posting under multiple names.

### Writing PLEASE HELP!!!!

i need a story that has a genre of realstic fiction please its due tomorrow!! Cold Mountain or Thirteen Moons by Frazier are two

### DrBob222 help me!!

Please I posted a chemistry question but I havent gotten any answer back please help me, sorry for having so little patience answered below.

### Critical Thinking

A strawman is when someone makes a claim,or refute by putting words in someones mouth.Please help I need an example sentence please!!!!!!!!!

### To FRANK or SUE - re DATABASE

1. Please release your Caps Lock key. 2. Copying/pasting is clearly not working for you. Please type in your question by hand.

### science

what is the word to put in the blank? A(n)_____________is a summary of what you have learned from an experiment. PLEASE help! whoever answers this please type an answer nicely. Thank You!!

### biology

what does the statement mean many discoveries lie in wait for the tools needed to make them? thank you.please i need the answer before i go to school in the morning. please help!

### biology

if hydrogen flouride (HF) is dissolved in pure water will the pH of the solution be lesser or greater than 7? please explain why? thank you so much ! please i need the answer tonight!!!!!

### third grade hw help

Hello All, Please help my son with his Math fraction. He needs to put the below fractions in ordedr from least to greatest. 1) 2/4, 2/3, 2/7, 2/5 2) 1/2, 6/7, 5/7, 1/10 3) 1/2, 6/7, 1/12, 2/3, 11/12, 1/6, 1/3, 1/4, 4/5 Please help!!! Thanks.

### Math

Hi - I'm finding this question a bit tricky and think I answered it wrong, can someone please verify for me? Many thanks.... In triangle EFG, find the value of f, if e = 7.3 cm, g = 8.7 cm and <E = 73. Please help

### Math(Please help, very confused!)

A piece of copper contains 3.6 x 10^8 atoms. What is the volume of the sample in units of liters? i have no idea how to start this. Please help thank you!!!

### Algebra

How do I solve these equations? I was out sick a whole week :( please no direct answers. I want to know the process as well. -a=5 4/5x=20 -2/3y=-18 -x/3=18 Please note that the / are fractions. Thank you so much in advance!! :)

### Algebra

Help please (x^3 + 3x^2 - 2x+7)/(x+1)=11 I don't how how to solve this at all-the answer should be 11 but I don't have a clue how to get it-please show me this one so I can hopefully do my homeowrk-we did this in class today but I don't understand it

### Math

Please check my answers and if there are any other possibilities then please tell me. List all the factors for 45: I got 1x45, 3x15 and 9x5. are there anymore?

### BIOLOGY please help!!

Negative allosteric effectors in the citric acicd cycle. Theres four: I have NADH and ATP What are the other two please help

### Psychology

Please help me: explain why individualistic and collectivistic cultures differ in their tendency to make the fundamental attribution error in. Please 80 to 100 words, Thank you in advance.

### math please help

Write an equality to describe the situation. A sleeping bag will keep a person warm in temperatures down to -20°F. Please I really need help.

### Social Studies

How did Diocletian try to reverse the decline of Rome? Please help! I don't get it :( Which event usually marks the fall of the Western Roman Empire? Please help!

### English help please

Which of the following personal completes the sentence correctly? One of my brothers just received ____diploma? A. his B. him C. their I think it is A or B. Can't quite decide. Please help.. Thank you

### College Algebra

Write the following a+bi form i(3.14-3i) Please help. I believe that the answer is 3.14i-3i, which would be (3.13*-1)-3*-1. however this was incorrect please tell me where I went wrong

### Algebra 1 (PLEASE HURRY!!)

{3x+y=-9 {-3x+-2y=12 What is the y-value of the solution to this system of equations? A. -7 B. -3 C. -2 D. -1 I tried them all and I must have did something wrong because none of them worked. Help please!! Thanks.

### ELA

What differences became matters of life and death during the Holocaust? There are no choices in the question. SOMEONE HELP ME PLEASE. MS. SUE, WRITETEACHER,SOMEBODY HELP ME PLEASE

### Math (exam tomorrow)

For the function f(x)=3cos(2x),what is the first point where it is increasing the fastest? Also please tell me how you know or derived that! Thank you!!! Please answer ASAP

### biology

someone please help me im confused and idk what im doingg how would i create a dna molecule model using straws, pushpins, and paperclips? help me, please.

### pre calc

Can someone please help me f(x)=1/3 square root 1-2x and g(x)= (x-2)/x. Find and simplify (g of g)(3)/(g of f)(-24). The answer I got it -24/7 and i Am unsure If it is correct. Please show all work Thank you

### Science please help

i am sorry to bother you Ms. Sue but i need to present your proposal of a device that minimizes heat transfer. can you please give a list of insulators

### maths

find the following square roots,using 'prime factors': i) 784 ii) 7056. 1 iii) 20---- 4 please give answers and tell me how to do. please

### math help please

unit 4 lesson 12 7th grade operations with fractions all 30 please I need it soon before I go visit my grandmother in the hospital

### physics

A gold wire 5.90m long and of diameter 0.890 mm carries a current of 1.21A. A)Find the resistance of this wire. B)Find the potential difference between its ends. Can someone please help me I don't know how to answer these questions? R=p(L/A) 1.21(5.90m/.890mm) Am i setting ...

### physics

(II) A grocery art with mass of 18 kg is pushed at constant speed along an aisle by a force F = 12 N. The applied force acts at a 20-degree angle to the horizontal. Find the work done by each of the forces on the cart if the aisle is 15 m long. Please help me solve step by step.

### physics

Hi! could anyone help me to solve this problem please. Three point charges are located at the corners of an equilateral triangle as in the figure below. Find the magnitude and direction of the net electric force on the 1.60 µC charge. (A = 1.60 µC, B = 7.20 µC, and C = -3....

### physics

a bullet with a mass of 5 g and a speed of 600 m/s penetrates a tree to a depth of 4 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. I used KE = 1/2 mv^2 = 900 J then F (friction ) = W/d = 22500 N BUT I don't know...

### physics

suppose a particular atom has only two allowable electron orbits. how many different wavelength photons (spectral lines) would result from all electron transitions in this atom? 1. three 2. four 3. None of these 4. one 5. two please help..

### Physics

a 35 g ice cube at 0.0 C is added to 110 g of water in a 62 g aluminium cup. The cup and the water have an initial temperature of 23 C . Find the equilibrium temperature of this system? in Celsius ,, I've been trying to solve this for 2 hours now , and I still can't get the ...

### physics

Which of the following statements is a consequence of equation E=mc^2? Energy is released when matter is destroyed Mass and energy are equivalent The law of conservation of energy must be modified to state that mass and energy are conserved in any process all of the above ...

### Physics.

A car starts a race from rest on a circular track and has a tangential speed of 43 m/s at the end of the third lap. The track has a radius of 91 m. If it has constant angular acceleration, what is the magnitude of its tangential acceleration? Help me and please explain in ...

### Physics Help

On the Acme W&W company production line, parts have to be transported 100 m by conveyor belt to a machine area. The parts move at a constant speed of 2.5 m/s. How much time does it take to move a part 100 m? Show steps please! Thank you!

### Physics

A block of iron at 415°C is put into a 0.625 kg tub of water at 15.0°C. They come to equilibrium at 100°C, and 0.144 kg of the water boils off to steam. What is the mass of the iron block? Please help, it keeps saying I have the wrong answer.

### physics

light travels from ethanol intro crown glass. what's the brewster angle in this situation? illustrate your answer with a light ray diagram. what's the signifcance of this angle of incidence? n1=1.36for ethanol nR=1.52 for crown glass tanangleB=nR/ni =1.52/1.36 =1.12 (48.2 ...

### I really need help!

Hi, I really need instructions. Can someone please tell me how to make a coordinate plane and a rectangle on the plane in Microsoft Excel 2013 please? I really I need an answer soon because this is due today!!!! Please someone help fast! Thank You :/

### physics

research on the physics of living systems.give to examples to show how physics help to understand the concepts of evolution,biological systems of living organisms.

### Math 116

7h+7j-6(7h-4j+5k) 7h+7h-6 Could help me with problem please, please

### Math

Please please....... What is the domain and range of y=3^x-4?????

### Math

Please Check My Answer Please!!! Thanks :) 9/4 = ?/12 54 36 45 27********* 27/90 = 3/? 3 10 9********** 27 32/? = 20/25 37 16*********** 26 40

### math

please answer these please??(studyguide) 6. 6 to 8 and 18 to x A.20 B.22 C.24 7.9/36 and x/4 A.1 B.4 C.9 8.42/22 and 21/x A.12 B.11 C.10 9.x/7 and 5/1 A.25 B.30 C.35 10.20/x and 4/8 A.35 B.40 C.48

### math

ratio please : (1 + 3 1/4) : (1 1/4 + 3 1/3) please teach me how to do it

### MATH

Please help, solution set for 7(4z-3)>59 please.?

### english

Hello! I'm a French student,I'm 17, I've learned the beginning of Freedom by Jonathan Franzen. Sometimes, it seems confused as it's my second language. So I need help, please. Can you explain what happened with Patty, Eliza, Carter, Richard and Walter in the chapter 2: best ...

### physics

Skye is trying to make her 70 kg St. Bernard go out the back door but the dog refuses to walk. If the coefficient of sliding fricction between the dog and the floor is .5, how hard must skye push in order to move the dog with a constant speed? please explain!

### physics

A 65.0-kg skier coasts up a snow-covered hill that makes an angle of 27.4° with the horizontal. The initial speed of the skier is 6.37 m/s. After coasting 2.07 m up the slope, the skier has a speed of 4.06 m/s. Calculate the work done by the kinetic frictional force that acts...

### physics

I'm having a really hard time with this physics problem...not really sure where to begin or which equation to use....please help: You are assigned the design of a cylindrical, pressurized water tank for a future colony on Mars, where the acceleration due to gravity is 3.71 ...

### math help please

Consider the function g(x)=x/x-7. a) Determine an equation for the vertical asymptote. b) State the domain. c) Determine an equation for the horizontal asymptote. d) State the range. e) Sketch the function. ( i will do it) f) Summarize the increasing and decreasing intervals. ...

### Physics Find mass and radius of planet.

While visiting Planet Physics, you toss a rock straight up at 15 m/s and catch it 2.4 s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 240 min. What is the mass of Planet Physics? What is the radius of Planet Physics?

### aig math(please answer)

4 kg of apples and 1 kg of berries cost $5.75 altogether. 2 kg of apples and 1 kg of berries cost a total of $3.25.How much must i pay to buy 5 kg of apples and 5 kg of berries?please show work. my answer is $10.50 am i right if not please tell me why and how?

### Physics

I have the equation 'change in distance = 1/2 x (vf+vi) x change in time (or delta t)' for uniform acceleration. However, I am totally lost when it comes to rearranging it. I need to rearrange it for inital speed (vi) and change in time (delta t). Can someone please help?

### 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 step me through the problem step by step?***

### Physics=Please check

I have an electrical circuit which has 20V shown on left side I=0.8A on top I = 0.3A on bottom I have to find the resistance Would I add 0.8 + 0.3 and then use the formula V = IR so it would look like this: 20V = 1.1A x R 20V x 1.1A = R

### PHYSICS HELP

A fibre is fixed at one end it is stretched over a pulley (2.0kg) is the mass. if the mass per unit length of the fibre is 82g/m, calculate the velocity of the wave on the stretched fibre. (please show working)

### URGENT: Please help with Physics

Suppose the mass of each of two spherical objects is doubled, and the distance between their centers is three times as large. How is the magnitude of the force of gravity between them affected? (Points : 5) It is 4/9 as large. It is 4/3 as large. It is 2/9 as large. It is 3/2 ...

### physics

The figure below shows three charges at the corners of a rectangle of length x = 0.65 m and height y = 0.42 m. What is the electric potential at the center of the rectangle? the picture is of a rectangle with -6.1,+2.7,-3.3 as charges. Your submitted answer is : -4.67e4 V I ...

### Physics

Sound of a certain wavelength is coming from within a room and passing through a rectangular door (a "slit"). If the width of the doorway is twice the wavelength of the sound, what is the diffraction angle è of the sound leaving the doorway? Please show me how to do this.

### running.from.myself

3. how many lines of symmetry are in a 8-sided snowflake? 10, 12, 8, 16 1. how many lines of symmetry are in a 6-sided snowflake? 10, 11, 12, or 6 if you wanted to make hearts on your snowflake,, which sides of the right triangle would you have to draw half of the heart? a. ...

### physics

PLease HeLP! You work for a moving company and are given the job of pulling two large boxes of mass m1 = 112 kg and m2 = 287 kg using ropes as shown in the figure below. You pull very hard, and the boxes are accelerating with a = 0.21 m/s2. What is the tension in each rope? ...

### Physics

In a friendly game of handball, you hit the ball essentially at ground level and send it toward the wall with a speed of 16 m/s at an angle of 32° above the horizontal. a) How long does it take for the ball to reach the wall if it is 5.2 m away? (b) How high is the ball when ...

### Physics please help!!

A school yard teeter totter with a total length of 5.46 m and a mass of 35.9 kg is pivoted at its center. A 17.7 kg child sits on one end of the teeter totter. Where should a parent push with a force of 272 N in order to hold the teeter totter level?

### Physics

(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**Scientist

Please help me with this!! I really can't find it. 1) This scientist used his device by dropped a spool of wire through a magnetic field. 2)This scientist used a torsional balance to show that the magnetic repulsion between magnetic poles varied by the square of the distance. ...

### math ergent please...

10.a)Solve the inequality x^3-5x^2+2x+8<0 by i) using intervals ii) considering all cases I did this but my teacher said that when i solved this: x^3-5x^2+2x+8<0 (x+1)(x^2-6x+8) (x+1)(x-4)(x-2)<0 She told me to show all the steps, but i don't know how to show more. so...

### 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

A charge of 28.0 nC is placed in a uniform electric field that is directed verticall upward and that has a magnitude of 4.00*10^4 N/C. What work is done by the electric force when the charge moves (a)0.450 m to the right (b) 0.670 m upward (c) 2.60 m at an angle of 45 degrees ...

### Physics

A 450 uF capacitor is charged to 295 V. Then a wire is connected between the plates. How many joules of thermal energy are produced as the capacitor discharges if all of the energy that was stored goes into heating the wire? I am totally confused I don't even know where to ...

### physics!

An electric car accelerates for 8.0s by drawing energy from its 320-V battery pack. During this time, 1300C of charge pass through the battery pack. Find the minimum horsepower rating of the car. I need some ideas to do it!!PLEASE HELP!!!THANK YOU SO MUCH!!!!

### physics help please....

After fixing a flat tire on a bicycle you give the wheel a spin. (a) If its initial angular speed was 5.17 rad/s and it rotated 10.6 revolutions before coming to rest, what was its average angular acceleration? rad/s2 (b) For what length of time did the wheel rotate? s

### physics please!

A 0.21 kg block oscillates back and forth along a straight line on a frictionless horizontal surface. Its displacement from the origin is given by x = (16 cm)cos[(16 rad/s)t + π/2 rad] What force, applied to the block by the spring, results in the given oscillation? why ...

### physics

The potential energy of a particle on the x-axis is given by U+ 8xe ^-xsquared/19 where x is 1 meter and U is in Joules. Please find the point on the x-axis for which the potential is a maximum or minimum. I've worked it three times and I get these three answers. Which one is ...

### physics

A bowling ball of mass 7.3 kg and radius 9.6 cm rolls without slipping down a lane at 3.4 m/s. Calculate its total kinetic energy. I tried this problem with the equation 3/4mv^2 but I did not get the correct answer, could I please get help with step-by-step explanation of how ...

### physics

A certain spring elongates 9 mm when it is suspended vertically and a block of mass M is hung on it. The natural frequency of this mass-spring system is: a)0.014 b)5.3Hz c)31.8Hz d)181.7Hz e)need to know M please explain the answer....and hope to answer soon.... thanks in advance

### 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 ...