126,957 results, page 2

### Physics

Can someone please tell me how to calculate the standard deviation of the following values? 0.985 0.985 1.005 1.455 1.035 And please for the following numbers too 1.47 1.52 1.50 1.45 1.39

Identify the action-reaction pairs in the following situations. (a) a man takes a step (b) a snowball hits a girl in the back (c) a baseball player catches a ball (d) a gust of wind strikes a window WE DIDN'T LEARN THESE PLEASE GIVE ME HELP/EXAMPLES

### Physics

Steel railroad tracks of length L = 18.30 m are laid at 10.0° C. How much space should be left between the track sections if they are to just touch when the temperature is T = 49.0° C? mm Please help. I have tried this L° α Δt = 18.3 * 13 10^-6 * (49 -10) = ....

### Physics

Please help!!! Physics test!? I have a physics test tomorrow on projectile motion, and I don't feel ready for it. I'm having trouble in the class and I need to ace this test. The problem is I get confused when I get a problem. I don't know how to proceed. After I read the ...

A 34 g glass thermometer reads 21.6°C before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 38.7°C. What was the original temperature of the water? -.135(4186)(Tf-38.7)=.034(840)(Tf-21.6) =-565.11Tf+21869.752=28....

### Physics

Please help me go through this F = q1q2/r^2, i know this is the equation, but i don't know how to get the answer, please help. What is the electric force between a +2 µC point charge and a –2 µC point charge if they are separated by a distance of 5.0 cm? Show your work...

### Physics

What is the average braking force required of a 1200kg car in order for it to come to rest from 60km/h in a distance of 25m Physics - Damon, Monday, September 1, 2014 at 6:51am Vi = 60 km/h (1 h/3600 s)(1000 m/km) v = Vi + a t 0 = Vi + a t t = -Vi/a d = Vi t + (1/2) a t^2 25...

### Physics

Can someone please explain how to tackle this problem? Cu - Anode electrode Zn - Cathode electrode A current of 2 amps is sustained for 16 minutes. what mass of Cu(s) is deposited on the zinc electrode? (Faradays' constant: 96500 C/mol e-) Please and thank you!!

### Physics

I am new at physics and having a very hard time. Could you please help. Thank you. Show that the water pressure at the bottom of the 50-m-high water tower in Figure 5.3 is 490,000 N/m2, or is approximately 500 kPa.

### Physics

someone please answer these Physics Q answers no explanation 1 What is the opposite force to gravity 2 an example of a contact force 3 an example of a non-contact force 4 What effect does ‘mass’ have on inertia 5 two examples of forces that could slow an object down 6 two ...

### physics - please explain further

Can someone please explain the answer I got for a question I previously posted on this page? I don't understand the solution I was given and even when I try it, I'm not getting the right answer.

bobpursley/ drwls please help me with my post on Sunday, April 15 at 10:16pm and 10:19pm. Thanks!

A 190 g particle is released from rest at point A inside a smooth hemispherical bowl of radius 25.0 cm. Calculate the gravitational potential energy at A also, how do you find kinetic energy if you aren't given velocity? please help me! i would really appreciate it

A very large firecracker explodes in the hallway into 3 fragments. Physics students rush to the scene to enrich their knowledge of the law of conservation of momentum. They report that Fragment 1: mass=1.23kg, v=8.70m/s, north Fragment 2: mass =2.60kg,v=6.10m/s,east fragment 3...

### Physics

i have just started physics, can someone please show me step by step how to do this: The radius of Earth is 6 370 000 m. Express this measurement in km in scientific notation with the correct number of significant digits. thank you for your help

Can you please check my physics posts. Thanks!

How many molecules are there in 0.029 moles of carbon dioxide gas, CO2? I asked this today, and the person told me to do 0.029 * 6.022e23 and my answer was wrong :/ Can someone please tell me what my answer should be!!?

Posted by Mary on Monday, September 3, 2007 at 12:40pm. download mp3 free instrumental remix A charge of +2q is fixed to one corner of a square, while a charge of -3q is fixed to the diagonally opposite corner. Expressed in terms of q, what charge should be fixed to the center...

### Religion

The 2nd harmonic of a string of length 60 cm and linear mass density 1.1 g/m has the same frequency as the 5th resonance mode of a closed pipe of length 0.8 m. Find the tension in the string.

I did this problem last night with Damon's help and I think it's correct at the end of the is-could you please check it? Calculate amount of energy needed to completely vaporize a 50g piece of 20 degree C silver melting point 1064 C L(f) = 64KJ/Kg Boiling point 2856C L(v) = ...

### Social studies?

Please ignore my previous post. I prematurely hit the enter key. I've been watching this board all day, waiting for someone to answer my physics question (no one has yet. sigh.) I just have to say Ms. Sue is my hero. She consistently answers almost every student's questions, ...

### Math And Physics

Law of Gravitation- Find an expression for the magnitude of the initial velocity that a projectile must possess in order to leave the earth when air friction is neglected. The gravitational constant for g is, G = 6.67428*10^-11 m^3 Kg^-1 s^-2 Please answer the question fully ...

On some planet with a radius of 8,553 km and a mass of 5.55 x 1024 kg the planet is spinning so fast such that anything at the equator will fly off of the planet. What is the planet's period (length of a day on the planet) in hours? Please help me solve !

If I have a roller coaster, and hill 1 height is 50cm and hill height 2 is 25 cm and the PE is .9 as it approaches the top of hill 2, how do I calculate the speed. Please help

### Physics

a car travels 59.78 miles east in 89.67 minutes, then 89.67 miles north in 59.78 minutes, and then 29.89 miles at 59.78 degrees west of south in 149.45 minutes. whats the magnitude of the car's average velocity in miles per hour??? Please help!!!!!! P.S. please don't round ...

### Typos, math, physics

Would everyone who posted math and physics problems this morning please go back and check for typos? It is difficult to guess what you mean and we do not have your text book.

### AP PHYSICS

A golf ball is hit with an initial velocity of 50m/s at an angle of 25° above the horizontal. A) How far does the ball travel? B) How high does the ball go? x-component: V= (50)cos25° = 45.32 m/s y-component: V= (50)sin25° = 21.13 m/s COULD YOU PLEASE HELP ME WITH THESE 2 ...

A spaceship lands on a new planet. the crew decides to measure the speed of sound in the planets atmosphere. taking a tube with a length of 50 cm, they find that one resonant frequency occurs at 2,520 Hz, and the next resonant frequency at 2,940 hz. what is the speed of the ...

### English

Scientists at Oak Ridge National Laboratory confirmed the existence of element 104 by creating 3000 atoms of it. If radioactive decay caused the number of atoms to drop by half within 4.0 s, how many atoms were left after 12 s? Show work please! Thank you!

### Physics

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um in diameter...

### Physics (SO CONFUSED!!!)

I think I'm using the wrong formulas or SOMETHING... Here's the question: "Two equal charges are separated by 3.7 ´ 10^-10 m. The force between the charges has a magnitude of 2.37 ´ 10^-3 N. What is the magnitude of q on the charges?" Here's my work: F = kc(q1q2/r^2) 2.37 x ...

### Physics

a car travels 59.78 miles east in 89.67 minutes, then 89.67 miles north in 59.78 minutes, and then 29.89 miles at 59.78 degrees west of south in 149.45 minutes. whats the magnitude of the car's average velocity in miles per hour??? Please help!!!!!! P.S. please don't round ...

### Physics

please tell me where I went wrong. A proton is moving parallel to a uniform electric field. The electric field accelerates the proton and increases its linear momentum to 5.0x 10^-23 kg m/s from 1.4x 10^-23 kg m/s in a time of 6.5x 10^-6 s. What is the magnitude of the ...

had this question last night for Dr. Bob-A fox sees a piece of carrion thrown from a nest 14 m high and goes to get it. Carrion is thrown 1.5 horizontal velocity. Fox is 7. m from base of tree. What is mgnitude of fox's average velocity if it grabscarrion just as it touches ...

### Math And Physics

Law of Gravitation- Find an expression for the magnitude of the initial velocity that a projectile must possess in order to leave the earth when air friction is neglected. The gravitational constant for g is, G = 6.67428*10^-11 m^3 Kg^-1 s^-2 Please answer the question fully ...

### NEED HELP ASAP PHYSICS@!!1

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

The heat of fusion for water is 3.3 x 105 J/kg. How much heat energy is needed to can 3kg of ice at 0°C to water at 0°C? Show your work. Help please!! Don't give the answer, but please help me find the answer?! Thanks

### College physics - Center of mass

College Physics- Center of Mass? The objects in the figure below are constructed of uniform wire bent into the shapes shown (Figure 1) . Each peice has a length of 0.15 . There are two objects that we need to figure out the x- and y-coordinates of the center of mass of the ...

A venturi tube is measuring the flow of water; it has a main diameter of 4.1 cm tapering down to a throat diameter of 1.8 cm. If the pressure difference is measured to be 67 mm-Hg, what is the velocity of the water? Please help step by step!!!

### Physics

Can someone please help me solve this question please: In the following position as a function of time equation, find the units of the constants A, B, and C. Where x is the position and has units of L, and v is velocity, and t is time.  x = Av + Bt^2 + C Thank you.

### Physics (my last problem)

A 3.4 kg ogject to the right at 3.5 m/s hits a stationary object of mass 2.7 kg. After the collision the 2.7 kg object moves to the right at 1.8 m/s. A) What is the final verlocity of the 3.4 kg object? B) What is the total kinetic energy og the objects before the collision? C...

A 3.00 kg toy falls froma height of 1.00m. What will the kinetic energy of the toy be just before it hits the ground. No air resistance and g=9.81m/s Amswers: 0.98J 9.8 J 29.4 J 294 J I used the formula 1/2 m times v^2 3. times 9.8^2/2 =144. Please help-what am I doing wrong?

### physics

please h t t p : / / w w w . j i s k h a . c o m / d i s p l a y . c g i ? i d = 1 2 5 2 8 9 5 3 6 7

What is the resistance of 125 m of aluminum wire that has a diameter of 0.8118 mm? The resistivity of aluminum is 2.824 x 10^-8 (omega) m. I need help with the set up. we've been using R = V/I, but haven't had anything with resistivity. I don't know where to place this, ...

### Physics Please someone help I don't understand it

A ship mapping the depth of the ocean emits a sound of 37 kHz. The sound travels to the ocean floor and returns 0.65 s later. (a) How deep is the water at that location? m (b) What is the wavelength of the wave in water? cm (c) What is the wavelength of the reflected wave as ...

You're on planet YZ and an astronaut observes that a 1.0 m long pendulum has a period of 1.50s. What is the free-fall accerlerttion on YZ? I know the answer is 17.6 because I worked it backwards but if the answer was given, I wouldn't know how to change the variables around-...

### Physics

How could you use 100 pounds of force to lift a 200 pound weight? Explain precisely, listing any necessary distances and details. (This will take some converting!) I don't understand this question, could someone please help me? I think I only need the distances from the ...

### Physics

How could you use 100 pounds of force to lift a 200 pound weight? Explain precisely, listing any necessary distances and details. (This will take some converting!) I don't understand this question, could someone please help me? I think I only need the distances from the ...

A small circular object with mass m and radius r has a moment of inertia given by I = cmr2. The object rolls without slipping along the track shown in the figure. The track ends with a ramp of height R = 3.0 m that launches the object vertically. The object starts from a ...

10pm. I asked "Show mathematically that to produce an image that is the same size as the object in a concave mirror, the object needs to be at twice the focal length from the mirror." and bobpursley answered: "1/o + 1/o=1/f 1/2f + 1/i=1/f 1/i=1/2f i=2f M=di/do= 2f/2f= 1 check ...

### pre ap physics

a car with amass of 1120 kg starts from rest and accelerates to the speed of 17.5 m/s in 18.8 s. assume that the force of resistance remains constant at 402.5 N during this time. what is the average power developed by the car's engine? answer in units of W can you please ...

### physics

please help There are six books in a stack, and each book weighs 5 N. The coefficient of static friction between the books is 0.2. With what horizontal force must one push to start sliding the top five books off the bottom one? please walk me through this

Distruive interference? Unless you put C in the line between A and B, this the asnwer is at infinity. Now on the line between A and B, the distance from A to C has to be an odd multiple of halfwavelength greater than C to B. Now, the distance between the speakers is two ...

### Physics.

A player kicks a football from ground level with an initial velocity of 28.8 m/s and 26 degrees above the horizontal. What is the ball's hang time? ______s What is the ball's maximum hight? ____ i am so confused on what type of equation i use! please help. I thought i would ...

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-Please check and I need help

Please help set this up- A person goes into the electric field and has an object with a charge value of 4.2E-6C. At a distance of 10m from the object that's responsible for the elctric field, the person sees a force of 8.0N on the object they have. What is electric field ...

R1= 10 ohm R2= 20 ohm R3= 50 ohm R4= ??? R1, R2, R3 and R4 are connected in parallel across a 120 V "power" supply to generate a current of 21 Amps. The value of R4 is most nearly _____ ohms. 0, 5, 10, 16, 100, 200, 300 I think 5 ohms, but I'm not sure...In need of some ...

### science

a planet orbits a star with period T. As seen from that planet the star's diameter subtends an angle of theta radians. Show the density of the star is given by rou=24pi/G(T^2)theta^3 please help!!!

### English

When is greatness is a bad thing. Please don't say when it is misused. I need a good answers please. Thanks in advamce. I don't understand your first sentence. Please clarify and repost. Please note that we don't do students' homework for them. Once you have come up with a ...

### Physics

please check: An ant on a picnic table travels 3.0 * 10^1 cm eastward, then 25 cm northward, and finally 15 cm westward. What is the magnitude of the ant's displacement relative to its original position i got 70 cm please help with this: For the winter, a duck flies 10.0 m/s ...

### College Physics

An x-ray photon collides head-on with an electron and is scattered directly back at 160◦ to its original direction. What is the shift in the wavelength of the incident x-ray? do i need to figure out the "compton shift" in order to solve..can someone please show me how to...

1. The centers of two 11.80 kg spheres are separated by 0.09 m. What is their gravitational attraction? 2. What is the ratio of this attraction to the weight of one of the spheres (at the surface of the Earth)? Please answer both Thank you

### Physics

I really don't get why I am getting this question wrong? Please can you explain to me how to do this question step by step so that I can understand it please? :( i have been stuck on this question for quite a while now. Determine the stopping distances for an automobile with ...

### Physics

I really don't get why I am getting this question wrong? Please can you explain to me how to do this question step by step so that I can understand it please? :( i have been stuck on this question for quite a while now. Determine the stopping distances for an automobile with ...

### Physics

I really don't get why I am getting this question wrong? Please can you explain to me how to do this question step by step so that I can understand it please? :( i have been stuck on this question for quite a while now. Determine the stopping distances for an automobile with ...

### Physics

I really don't get why I am getting this question wrong? Please can you explain to me how to do this question step by step so that I can understand it please? :( i have been stuck on this question for quite a while now. Determine the stopping distances for an automobile with ...

Geosynchronous satellites orbit the Earth at an altitude of about 3.58×10^7 m. Given that the Earth's radius is 6.38×10^6 m and its mass is 5.97×10^24 kg, what is the magnitude of the gravitational acceleration at the altitude of one of these satellites? Please explain as ...

### Physics

PLEASE ANSWER ASAP!!!!!!!!!!!!!!!!!!!!!!! a cross country runner runs 3km due east, 5km due south and 8km south west. what is the runners final displacement and what direction in true bearing form? PLEASE CAN YOU EXPLAIN IT STEP BY STEP

### Physics

"It takes a force of 109 N to lift a stone straight up. This force gives the stone an acceleration of 12 m/s^2. Calculate the mass of the stone." My physics teacher tried to explain this problem to us, but he explained it so confusingly that I still don't get it (if that made ...

### PHYSICS

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um in diameter...

### physics

please help! physics doesn't click with me. thank you for your help! A 23 kg suitcase is being pulled with a constant speed by a handle that is at an angle of 25° above the horizontal. If the normal force exerted on the suitcase is 155 N, what is the force F applied to the ...

### Note to physics, chemistry students

Please note the spelling of Physics, and Chemistry. If you are a college student in those courses, and cant spell them, frankly, asking for help here is insulting to your college and you.

### Physics

Physics Question Please Help? A wire, 20.0 m long, moves at 4.0 m/s perpendicularly through a magnetic field. An EMF of 40V is induced in the wire. What is strength of the magnetic field?

A block of mass is moving along the horizontal frictionless surface with a speed of 5.70 m/s. If the slope is 11.0° and the coefficient of kinetic friction between the block and the incline is 0.260, how far does the block travel up the incline? Show step by step please! ...

A 35-mm camera equipped with a 40-mm focal length lens is used to photograph a tree 17 m tall. If a 32-mm high image of the tree on the CCD sensor is required, how far should the camera lens be from the tree? Show Work Please! Thank you so much!

A 35-mm camera equipped with a 40-mm focal length lens is used to photograph a tree 17 m tall. If a 32-mm high image of the tree on the CCD sensor is required, how far should the camera lens be from the tree? Show Work Please! Thank you so much!

### Physics

A cube of ice is taken from the freezer at -8.8°C and placed in a 103 g aluminum calorimeter filled with 321 g of water at room temperature of 20°C. The final situation is observed to be all water at 15°C. What was the mass of the ice cube? Could someone please help me get ...

### Physics sorry for reposting but I really need help

An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...

### Algebra

While visiting Planet Physics, you toss a rock straight up at 13.6 m/s and catch it 3.50 s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 340.0 minutes. What is the mass (in kg) of the planet?

While visiting Planet Physics, you toss a rock straight up at 13.6 m/s and catch it 3.50 s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 340.0 minutes. What is the mass (in kg) of the planet?

### Physics

A rock is thrown off a bridge at an angle of 38degree above horizontal, and landed in the water 3.60 seconds later 60.0 meters from the point at the waters level directly below the thrower... What is the rock's horizontal velocity? I need better clarity on physics, please?

A skier slides horizontally along the snow for a distance of 11.9 m before coming to rest. The coefficient of kinetic friction between the skier and the snow is 0.0458. Initially, how fast was the skier going? I do not know how to start this. Thank you. Physics(Please help) - ...

### physics

A batted baseball, which leaves the bat at an angle 〖30〗^0 above the horizontal, is caught by an outfielder 120m from the plate. a.) What is the initiated velocity of the ball? b.) How high did it rise? c.) How long was it in the air? my friend asked that ...

### physics

Hi, can someone please help with this question. A thin, uniform rod is bent into a square of side length a. If the total mass is M, find the moment of inertia about an axis through the center and perpendicular to the plane of the square. Use the parallel-axis theorem. Express ...

### physics

I am to measure the deflection by contructing a post and lintel system using the dowels I have (with different diameters, which will be my variables). I want to create a chart to present my results, but I don't know what I need to measure or what to look for. Please help me. ...