Tuesday
January 24, 2017

# Posts by Physics

Total # Posts: 423

Physics
I'm given two cars A and B Car A is 1100 kg and traveling at 11 m/s Car B is 1400 kg and traveling at 15 m/s and I'm asked to fidn the velocity of both is just the net velocity 4 m/s ??? I'm also to find the impulse and how would I do that??? impulse is chang in ...
June 17, 2009

Sarah
they got it in cm so 17.6 cm
June 15, 2009

Sarah
A light spring having a force constat of 125 N/m is used to pull a 9.50kg sled on a horizontal frixtionless ice rink. If the sled has an acceleration of 2.00 m/s^2, by how much does the spring stretch if it pulls on the sled (a) horizontally, (b) at 30.0 degrees above the ...
June 15, 2009

mary
The question is: a horizontal force of magnitude 22.0 N is applied to a 2.86 kg book as the book slides a distance d = 0.73 m up a frictionless ramp at angle θ = 30°. The book begins with zero kinetic energy. What is its speed at the end of the displacement? I did W=...
June 7, 2009

Physics
Hello can some one show and exlpain to me the derivation of this formula? V = (Ft(mL^-1)^-1)^(2^-1) or simply V = sqrt (F/(m/L)) were V = the veloctiy of a piece of string Ft = the force of tension m = mass L = length Thank you!
June 7, 2009

jane
1. a centripetal-acceleration addict rides in uniform circular motion with period T=2s and radius r=3m. at t1 his acceleration vector= 6(m/s^2)i + -4(m/s^2)j. At that instant, what are the values of vector b (dot) vector a and vector r (dot) vector a All I could figure out was...
June 2, 2009

charley
tinyurl--qwxgbv (The qwxgbv is after the slash) The proton moves through a magnetic field of magnitude 3x10^-5 T with a velocity of 4x10^5 m/s. Find the radius of the circular path the proton follows and indicate its direction of rotation.
May 27, 2009

Physics
I don't know how to answer this questin i guess I don't understand the definition A streteched sgtring fized at both ends is 2.0 m long. What are three wavelengths that will poduce standing waves on the string? Name at least one wavelenght that would not produce a ...
May 24, 2009

Physics
How do i Do this A wave of amplitude 0.30 m interfers witha second wave of amplitude 0.20 m. What is the largest resultant displacement that may occur?
May 23, 2009

Physics
I lied I didn't get kg^(1/2) m^(1/2) s like I said before I prove my answer I got this which is the last line of my proof (Kg^(1/2) s)/(m^(1/2))
May 7, 2009

Physics
Hello recently I was asked to find the time it takes a satalite that is geocentric (that always stays above the same exact spot of the earth) so... I was given the radius of 61 earth radius or simply 3.89 E 6 m mass of earth what G equals and have to use Newtons law of ...
May 7, 2009

Physics
I'm not exactly sure how to do this problem The Earth has a radius of 6.37E6 meters. Draw a picture and calculate: - The circumference of the Earth - The time for one rotation of the earth in seconds - The velocity of someone standing on the equator - The centripetal ...
May 3, 2009

Physics
I'm not exactly sure how to do this problem The Earth has a radius of 6.37E6 meters. Draw a picture and calculate: - The circumference of the Earth - The time for one rotation of the earth in seconds - The velocity of someone standing on the equator - The centripetal ...
May 3, 2009

physics
So I got this little sheet called Shoot the Chute To be sure you understand the preceeding question and answer, consider this one: A roller coaster is pulled to the top of a "shoot the chute" and allowed to roll down. For a bigger thrill you might wish the car to be ...
March 24, 2009

physics
please check my answer An electron moves north at a velocity of 9.8 * 10^4 m/s and has a magnetic force of 5.6 * 10^-18 N west exerted on it. If the magnetic field points upward, what is the magnitude of the magnetic field? F=BqV F= 5.6 * 10^-18N q= 16 * 10^-19C V= 9.8 * 10^4 ...
March 19, 2009

Physics
could you tell me how to solve for accerating force above friction force? my problem was down below the topic science again
March 18, 2009

Physics
A 15 N wooden block is dragged for 15 meters across a wooden floor in 15 seconds... I'm given that the mew (the greek leter uk) or however u say it is .2 I have to make a free body diagram I sloved and got Fn = 15 N mg = -15 N Ff = -3 N How do I solve for the force applied...
March 18, 2009

physics
please tell me if this is correct, A step-down transformer has 16000 turns on the primary and 95 turns on the secondary. If the rms emf across the secondary coil is 120 V, what is the maximum emf across the primary coil? is the answer 28577.69 V ?
March 17, 2009

physics
please tell me if thsi si correct 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 changes? f=1/4pi Er * q^2/r^2 2.37 * 10^-3 = 9*10^9 * q^2 ______________ (3.7 * 10^-10)^2 3....
March 17, 2009

physics
two point charges are 10.0 cm apart and have chargeso of 2.0 uC (micro)and -2 uC, respectively. What is the magnitude of the electric field at the midpoint between the two charges? i think i know how to do it: both E1 and E2 go in the same direction E1=0.72 * 10^7 and E2 = 0....
March 15, 2009

physics
ok, thanks
March 15, 2009

physics
is it .24 amps?
March 15, 2009

physics
The potential differnece across a resistor is 4.4 * 10^2 V. If the resistance of the resistor is 1.8 k ohms, how much current flows throught the resistor? R=1.8 k ohms I=? 4.4*10^2 V V=IR I=V/R = 4.4 * 10^2 ___________ = 2.44*10 1.8 * 10^ 24.4 A is this done correctly?
March 15, 2009

physics
but i checked and it does point in the opposite direction the charges are differnect signs..... i'm confused!
March 15, 2009

physics
two point charges are 10.0 cm apart and have chargeso of 2.0 uC (micro)and -2 uC, respectively. What is the magnitude of the electric field at the midpoint between the two charges? i think the answr is zero.. but i don't understand how to get to it...can you please show me...
March 15, 2009

physics
pleae check How is current affected if the time interval over which the charge passes through a given area decreases while the amount of charge remains the same? a. the current increases b. the current decreases c. the current initially increases and then is gradually restored...
March 14, 2009

physics
What effect will be produced on a capacitor if the separation between the plates is increased? a. it will increase the charge b. it will decrease the charge c. it will increase the capacitance d. it will decrease the capacitance D A 0.25 uF capacitor is connected to a 9.0 V ...
March 14, 2009

physics
please check: A battery converts what type of energy into electrical energy? a. mechanical b. nuclear c. solar d. chemical D When a parallel-plate capacitor is connected to a battery:a____ is stored on one plate, and a ___ is stored on the other a. negative charge, positive ...
March 14, 2009

physics
please check Which of the following is NOT a characteristic of electrical potential energy? a. it is a form of mechanical energy b. it results from a single charge c. it results from the interaction between charges d. it si associated with a charge in an electric field A
March 14, 2009

physics
please check: Two point charges, initially 1 cm apart, are moved to a distance of 3 cm apart. By what factor do the resulting electric and gravitational forces between them change? a. 9 b. 3 c. 1/3 d. 1/9 D Two positive charges, each of magnitude q, are on the y-axis at points...
March 14, 2009

physics
please check: Conductors can be charged by ___, while insulators cannot. a. grounding b. induction c. polarization d. contact D Which of the following is not true for both gravitational and electric forces? a. the inverse square distance law applies b. forces are proportional ...
March 14, 2009

physics
please check this: Which sentence best describes electrical conductors? a. electrical conductors have low mass density b. electrical conductors have high tensile strength c. electrical conductors have electric charges that move freely d. electrical conductors are poor heat ...
March 14, 2009

physics
please check this: When a glass rod is rubbed with silk and becomes positively charged, a. electrons are removed from the rod b. protons are removed from the silk c. protons are added to the silk d. the silk remains neutral A Charge is most easily transferred in a. ...
March 14, 2009

physics
A certain radio wave has a frequency of 2.0*10^6 Hz. What is its wavelength? c=3*10^8 m/s wavelength = 3*10^8 _______ 2*10^6 = 150 m is this done correctly?
March 14, 2009

physics
Monochromatic light from a helium-neon laser (wavelength=632.8 nm) shines at a right angle onto the surface of a diffraction grating that contains 130 960 lines/m. Find the angle at which one would observe the first-order maximum. formula: (a+b)Sin theta = n wavelength (a+b...
March 14, 2009

physics
The critical angle of refraction for calcite is 68.4 degrees when it forms aboundary with water. Use this information to determine the speed of light in calcite. refaraction index 'n' n=cosec 68.4degrees n=1.07 is this done correctly?
March 14, 2009

physics
can you check this : a repelling force occurs between two charged objects when the charges are of a. unlike signs b. like signs c. equal magnitude d. unequal magnitude i chose B
March 14, 2009

physics
An elevator weighing 2.00*10^5 N is supported by a steel cable. What is the tension in the cable when the elevator is accelerated upward at a rate of 3.00 m/s^2? (g=9.81 m/s^2) weight = mg = 2*10^5N = m(9.8) = 2*10^5N mass = m = 2*10^5kg _________ 9.8 = 2.04*10^4kg T-mg=ma T=m...
March 14, 2009

physics
so, how would i write it out? = -0.544 - -3.40 ????????
March 14, 2009

physics
there is a figure that looks kind of like this: E6--------------------- E= -0.378eV E5--------------------- E= -0.544eV E4--------------------- E= -0.850eV E3--------------------- E= -1.51eV E2--------------------- E= -3.40eV the figure shown above shows the enrgy levels for a...
March 14, 2009

physics
ok, thanks...i just want few other people to reply to this post...just to be sure i agree with you but int the one "which of the following statements about electromagenetic..." i'm not sure between B and D thanks again
March 14, 2009

physics
please check these: Which interaction of nature binds atoms and molecules by attracting unlike charges and repulsing like charges? a. strong b. weak c. electromagnetic d. gravitational i got A, but someone said C , so i just want to make sure How is a motor's mechanical ...
March 14, 2009

physics
is this done correctly? A step-down transformer has 16000 turns on the primary and 95 turns on the secondary. If the rms emf across the secondary coil is 120 V, what is the maximum emf across the primary coil? Np=16000 Ns=95 turns Vs=120V Vp=? Ns Vs ___ = ____ Np Vp Ns*Vp=Vs*...
March 13, 2009

physics
A concave mirror forms a real image at 17.0 cm from the mirror surface along the principal axis. If the corresponding object is at ta distance of 36.0 cm, what isi the mirror's focal length? let u be the object distance let v be the image distance v=17 cm u=36 cm 1/f = 1/u...
March 13, 2009

physics
If you stand 3.0 m in front of a flat mirror, how far away from you would yourimage be in the mirror? 6.0 m If light waves are coherent, a. they shift over time b. their intensity is less than that of incoherent light c. they remain in phase d. they have less than three ...
March 13, 2009

physics
please check this one question: Which interaction of nature binds atoms and molecules by attracting unlike charges and repulsing like charges? a. strong b. weak c. electromagnetic d. gravitational A
March 13, 2009

physics
please check these: A concave mirror with a focal length of 10.0 cm creates a real image 30.0 cm away on its principal axis. How far from the mirror is the corresponding object? a. 20cm b. 15cm c. 7.5cm d. 5.0cm B A diffraction grating that contains 650 472 lines/m is ...
March 13, 2009

KC
I have an assignment to discuss what scientists are doing to reduce the g forces on astronauts and to come up with a g force problem of my own. Can you help?
March 13, 2009

KC
Is anyone aware of some good links to sites which discuss and explain G-Force? I've searched but haven't come up with anything very worthwhile.Something with practice problems would be great. Thanks!
March 13, 2009

physics
according to Lenz's law, the magnetic field of an induced current in a conductor will a. enhance the applied field b. heat the conductor c. increase the potential difference d. oppose a change in the applied magnetic field i think D
March 12, 2009

physics
check which of the following modifications to a solenoid would be most likely to decrease the strength of its magnetic field? a. removing its iron rod core and increasing the number of coils b. increasing the current and reducing the number of coils c. reducing the number of ...
March 12, 2009

physics
then it's A?
March 12, 2009

physics
drwls said this is wrong but i don't know what's correct the enregy gained by electrons as they are accelerated by an electric field is a. greater than the average loss in energy due to collissions b. equal to the avergae loss in energy due to collissions c. less than ...
March 12, 2009

physics
thanks!
March 12, 2009

physics
please check these 3: if the batteries in a portable CD player provide a terminal voltage of 12 V, what is the potential difference across the entire CD player? a. 3.0 V b. 4.0 V c. 6.0 V d. 12 V D two resistors having the same resistance value are wired in parallel. how does ...
March 12, 2009

physics
i'm still getting C as the answer to this one drwl said its wrong When a positive charge moves in the direction of the electrical field, what happens to the electrical potential energy associated with the charge? a. increase b. decreases c. remains the same d. increases ...
March 12, 2009

physics
ok, :)
March 12, 2009

physics
nevermind i think its A can you check that?
March 12, 2009

physics
i can not find the correct answer for this one i got D but someone siad its wrogn electric field strength depends on a. charge and distnace b. charge and mass c. Coulomb constant and mass d. elementary charge and radius
March 12, 2009

physics
If atmospheric refraction did not occur, how would the apparent time of sunrise and sunset be changed? a. both would be later b. both would be earlier c. sunrise would be later, and sunset would be earlier d. sunrise would be earlier, and sunset would be later C drwls told me ...
March 12, 2009

Physics
what would be the appropriate answer choice for this question: If the batteries in a portable CD player provide a terminal voltage of 12 V, what is the potential difference across the entire CD player? a. 3.0 V b. 4.0 V c. 6.0 V d. 12 V thanks alot guys
March 12, 2009

physics
please check these for me: When a positive charge moves in the direction of the electric field, what happens to the electrical potential energy associated with the charge? a. it increases b. it decreases c. it remains the same d. it sharply increases, and then decreases C A ...
March 12, 2009

physics
please check these for me: If atmospheric refraction did not occur, how would the apparent time of sunrise and sunset be changed? a. both would be later b. both would be earlier c. sunrise would be later, and sunset would be earlier d. sunrise would be earlier, and sunset ...
March 12, 2009

French Cuisine (Check)
wow, it sounds really good but i think there might be a few spelling or grammatical errors, i found one:like 'seamed' which should be 'seemed'
March 12, 2009

physics
please check these for me: What is the wavelength of microwaves of 3.0*10^9 Hz frequency? a. 0.050m b. 0.060m c. 0.10 m d. 0.20 m C If a light ray strikes a flat mirror at an angle of 30deg from the normal, the ray will be reflected at an angle of a. 30deg from the mirror'...
March 12, 2009

physics
pleaase help me with this, i'm very bad in physics, and i mostly don't understand any of this stuff...can anyone explain as well as show me how to do this Monochromatic light from a helium-neon laser (wavelength=632.8 nm) shines at a right angle onto the surface of a ...
March 12, 2009

physics
how would i go about solving this problem? what formula shoud i use? can you please show me in steps how to do this, thanks a lot: The critical angle of refraction for calcite is 68.4degrees when it forms a boundary with water. Use this information to determine the speed of ...
March 12, 2009

History
the confederates also thought that if they had a choice to be a united nation, they also had a choice to leave it.
March 12, 2009

MATH
11/5 is an improper fraction, once you divide it, it will become a mixed number like MS.Sue said, 2 1/5
March 12, 2009

physics
please help: A repelling force occurs between two charged objects when the charges are of a. unlike signs b. like signs c. equal magnitude d. unequal magnitude
March 12, 2009

physics
here is my problem: a concave mirror forms a real image at 17.0 cm from the mirror surface along the principal axis. if the corresponding object is at a distance of 36.0 cm, what is the mirror's focal length? here's my work: 1/f = 1/v + 1/u where f=focal length=? u= -...
March 12, 2009

physics
please check these: a laser can be used a. to treat glaucoma b. to measure distance c. to read bar codes d. all of the above D in a laser, all of the following forms of energy can be converted into coherent light except a. chemical energy b. electrical energy c. light d. ...
March 11, 2009

physics
here is my problem: a concave mirror forms a real image at 17.0 cm from the mirror surface along the principal axis. if the corresponding object is at a distance of 36.0 cm, what is the mirror's focal length? here's my work: 1/f = 1/v + 1/u where f=focal length=? u= -...
March 11, 2009

physics
here is my problem: a concave mirror forms a real image at 17.0 cm from the mirror surface along the principal axis. if the corresponding object is at a distance of 36.0 cm, what is the mirror's focal length? here's my work: 1/f = 1/v + 1/u where f=focal length=? u= -...
March 11, 2009

physics
so Tf is 84.70?
March 11, 2009

physics
find the final equilibirum temperature when 10.0 g of milk at 10.0degC is added to 1.60*10^2 g of coffee with a temperatrure of 90.0degC. Assume the specific heats of coffee and milk are the same as for water (Cp,w=4.19J/g*degC) and disregard the heat capacity of the container...
March 11, 2009

physics
March 11, 2009

physics
here is my question: A bullet with a mass of 6.00 g is fired through a 1.25 kg block of wood on a frictionless surface. The initial speed of the bullet is 896 m/s, and the speed of the bullet after it exits the block is 435 m/s. At what speed does the block move after the ...
March 11, 2009

physics
A certain radio wave has a frequency of 2.0 * 10^6 Hz. what is its wavelength?
March 11, 2009

history
so its A
March 11, 2009

KC
Great! thanks a lot.
March 11, 2009

KC
When a plane experiences a decrease in weight must there also be decrease in lift? I'm thinking the answer is yes in order to maintain equilibrium.
March 11, 2009

Brock
An object creates an inverted, virtual image, 3 cm tall, 10 cm from a converging mirror with a focal length of 15 cm. Where is the object located? How tall is it? I didn't think mirrors created inverted virtual images...
February 24, 2009

Physics
A box slides down a 30.0 degree ramp with an acceleration of 1.20 m/s^s Determine the coefficent of kinetic friction between the box and the ramp How on earth do I do this with only this amount of information???
February 3, 2009

Physics
Yah i got another question a large crate is placed on the bed of a truck but is not tied down as the truck accelerates forward the crate slides across the bed until it hits the tailgate explain what causes this i'm completley lost
February 2, 2009

Physics
An object thrown into the air stops at the highest pooint in its path is it in equilbrium at this point explain? I siad yes because it's moving for that one breif moment I wasn't sure or not so I'm asking to see if this is right
February 2, 2009

Physics
here's another one that i have no idea how to do If a car is accelerating downhill under a net force of 3674 N what force must the brakes exert to cuase the car to have a constant velocity?
February 2, 2009

Physics
well the net force is obivuosley greater than friction sense it's moving allowing it to move 20 m/s f=ma i don't know the mass so I don't know what to do here?
February 2, 2009

Physics
I don't see how I have enough information to answer this question If a car is traveling westward with a constant velocity of 20 m/s what is the net external velocity
February 2, 2009

physics
odd i never seen this formula before and we haven't goten to tension yet thank you
January 28, 2009

physics
A 5.0 kg bucket of water is raised form a well by a rope. If the upward acceleratiopn of the bucket is 3.0 m/s^2 find the force exerted by the rope on the bucket of water what exactly do i do here? 3.0 m/s^2 upward? is this the Fn? I have no idea how to do this problem...
January 28, 2009

Physics
A 2.0 kg mass starts from rest and slides down an inclined plane 8.0 X 10^-1 m long in .50s. what net force is acting on the mass along the incline. I have no idea how to do this I don't know why they just didn't say .8m the back of the book says 13 N down the incline ...
January 28, 2009

Physics
A box slides down a 30.0 degree ramp with an acceleration of 1.20 m/s^2. Determine the coefficient of kinetic fiction between the box and ramp. I'm not exactly sure what to do here I know the formulas are uk = Fk/Fn Us = Fs, max/Fn not exactly sure how to do this problem ...
January 28, 2009

Peter
A 200 N/m, 5 m spring on a 20 degree incline is compressed 2.3 m and a 5 kg block is placed on it. If we neglect friction, how far up the incline will the block travel? How fast will it be traveling when it is 0.2 m up the incline?
January 15, 2009

physics
January 15, 2009

Physics
sigh this is killing me here... ok rockets launch at 250 m/s @ an angle of 75.0 degrees. There's a mountain 2500m away from launch point that is 1800m high. There's a boat 610 m from the island. So i'm suppose to find out how much it'll clear the moutain and ...
January 14, 2009

physics
sigh this is killing me here... ok rockets launch at 250 m/s @ an angle of 75.0 degrees. There's a mountain 2500m away from launch point that is 1800m high. There's a boat 610 m from the island. So i'm suppose to find out how much it'll clear the moutain and ...
January 14, 2009

physics
i have to build a catapult that will fire a projectile that will pass a 1m tall wall 1 m away from starting point and land in a target 1 m away from the wall. the catapult cant be more than 23cm high. I'm having some problems here with this for simpicity issues i said ...
December 25, 2008

physics
the other physics question
December 22, 2008

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