Friday

April 18, 2014

April 18, 2014

Total # Posts: 361

**physics**

I was taking upwards in the y direction positve and downwards in the y dierction negetive my bad

**physics**

a = m2^-1 (m1 a) -g solve for acceleartion it's the same post below they cancel out

**prealgebra**

y^2 + 6y -12 y -72 simplify

**Algebra**

I think you mean the limits

**Physics**

ok how do I solve for a m1 a - m2 g = m2 a

**Physics**

I've asked a similar qustion earlier and now I think I have drawn the correct free body diagram and go about solving the problem. The only thing is I do not know how to solve it. a block (mass m1) on a smooth horizontal surface, connected by a thin cord that passes over a ...

**Physics**

Ok I guess the reason why I do not know how to do this problem is because I can not draw the proper free-body diagram... Three blocks on a frictionless horizontal surface are in contact with each other as shown in Fig. 4-5. A force F is applied to block 1 (mass m1). (a) Draw a...

**Physics**

is this right? ------Force F onto m1--->|m1| ---contact force onto m2--->|m2|-----contact force onto m3---->|m3|

**Physics**

Ok I guess I'm drawing the free body diagram wrong how do I draw it because this is not making much sense to me

**Physics**

I got two questions Three blocks on a fricitonless horizontal surface are in contact with each other a force F is applied to block 1 mass m1 Draw a free body diagram for each block ok done the accelration of the system (in terms of m1, m2, and m3) ok done I got a = (m1 + m2 + ...

**Physics**

Ok I got a question I asked before except there are other parts that I didn't ask so here we go Three blocks on a frictionless horizontal surface are in contact with each other A force F is applied to block 1 (mass m1). Draw a free-body diagram for each block ok I did this...

**Physics**

I'm also kind of lost on how to draw the free body diagram of the first block the force F points to the right right? what points to the left <-----| m1 |------> F what points to the left I know the rest for m1 i think If i drew force F corectly on block m1 and how do...

**Physics**

Three blocks on a frictionless horizontal surface are in contact with each other A force F is applied to block 1 (m1) Draw a free body diagram for each block ok for the diagram is the force F applied horizontal to mass one does this force act on m2 all the blocks are lines up ...

**Physics**

oh... lol thanka

**Physics**

hmmm aparently that's not how you do it hmmm could you please show me how to get the time step by step don't you have to use this equation X = 2^-1 a t^2 + Vo t + Xo write it in the second dimension Y = 2^-1 g t^2 + Vo t + Yo and sense there is no Yo I get this Y = 2^-...

**Physics**

Ok I asked this question before A lbock is given an intial speed of 4.0 s^-1 m up the 22 degree plane How far up the plane will it go ok I got this to be something like 2.2 about i understand this i need help on this how much time elapses before it returns to tis starting poin...

**Phyiscs**

A lbock is given an intial speed of 4.0 s^-1 m up the 22 degree plane How far up the plane will it go ok I got this to be something like 2.2 about i understand this i need help on this how much time elapses before it returns to tis starting point? Ignore friction. ok I need to...

**Physics**

ok well obviously mg is the hypotenuse and the force in the x direction is the opposite obviously but what triangle is this???? how is mg the hypotenuse and the force in the x direction the opposite??? what triangle gives us this??? with reference to what angle were only given...

**Physics**

I'm tyring to undersatnd uh motion of a particle at an incline on a ramp with a certain angle with the horizontal. the force pointing downwards is mg the force that is pointing upwards exerted by the ramp onto the the particle is the normal force which is not pointing perf...

**Physics**

I posted this question earlier and I still don't get it So I got a question One 3.5-kg paint bucket is hanging by a massless cord from another 3.5-kg pain bucket, aslo hanging by a massless cord if the buckets are at rest, what is the tension in each cord? How do I do this...

**Physics**

So I got a question One 3.5-kg paint bucket is hanging by a massless cord from another 3.5-kg pain bucket, aslo hanging by a massless cord if the buckets are at rest, what is the tension in each cord? How do I do this is this just the normal or what I do not understand how you...

**Physics**

ok thanks

**Physics**

ok so I have a question At the instatn a race began, a 57-kg sprinter was found to exert a force of 80 N on the starting lbock at 22 degrees with respect to the ground what was the horizontal acceleration of the sprinter? I got roughly 1.3 s^-2 m ok here's were i need some...

**Physics**

ok uh I still don't completly understand I thought I was trying to get it to point westward not south west also what about the basketball player question

**Physics**

I have two questions this one A 750-N force acts in a northweserly direction. A secon 750-N force must be exerted in what direction so that the resultant of the two forces points westward? I have no idea how to go about solving this prolbem second Draw the free body diagram fo...

**Physics**

When I asked my teacher for help he told me this This is a logical puzzle. Having 75% of the typical weight means experiencing 75% of the typical gravity. The floor must be falling away with an acceleration of 25% of typical gravity. Here's the question I asked that's ...

**Physics**

My question is A block is given an intial speed of 4.0 s^-1 m up the 22 degree plane How far up the plane will it go? How much time elapses before it returns to its starting point? Ignore friction. Ok my teacher said use this to find acceleration a = g sin è and then I ...

**Physics**

what is newtons method isn't the formula suppose to be y = Vo t - 2^-1 g t^2 ????? -1.5 = u sin(10) -(1/2)g t2 instead of that shouldn't it be -1.5 = (u sin(10))? -(1/2)g t2

**Physics**

Ok the problem I'm doing has two parts I know how to do part a and got the right answer I think... I do not know how to do part b Here's the problem A student driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp (a)With what minimum...

**Physics**

thanks a bunch I guess i didn't see the importance of the word horizontal THANKS!!

**Physics**

A ball is thrown horizontally from the roof of a building 9.0 m tall and lands 8.5 m from the base. What was the ball's intial speed? I have no idea how to do this problemm or what formulas to use because of the fact that I do not know the time interval it took to fall. Se...

**Physics**

huh ok thanks i thought sense the end vector was south perfectly south... ok makes sense direction of displacement vector I guess is what it means by direction... Thanks!

**Physics**

A delivery truck travels 18 blocks north, 10 blocks east, and 16 blocks south. what is its final displacement from the origin? assume the blocks are equal length. My only question is I got about 10 blocks for the displacement got a 2 opposite and 10 adjacent and had to solve f...

**Physics**

I'm trying to rearange this 0 = Xo + 2^-1 a t^2 for t I've been told that it is (a^-1 2x)^(2^-1) but I do not see how please show me step by step how you get that 0 - Xo = Xo - Xo + 2^-1 a t^2 (-Xo = 2^-1 a t^2) a^-1 2 (a^-1 (2-Xo) = t^2)^(2^-1) (a^-1 (2 - Xo))^(2^-1) ...

**Physics**

when trying to find uncertanty percent error and your given the number - 15 s^-2 m with a implied uncertanty of +/- 1 s^-2 m and you try to find the percent uncertanty and you do this (- 15 s^2 m)^-1 1 s^-2 m (100 %) is the percent negative or positve also when trying to find ...

**physics**

the speed of a car can be measured in s^-1 m right... it could be said that a speed of a car the velocity was 15 s^-1 m which is perfectly acceptable... by definition 15 s^-1 m can also be written as 15 Hz m just by definition... what on earth does that mean??? is velocity not...

**physics**

Thank You

**physics**

can you show me how to do this mathematically A car traveling 90 km/h is 100 m behind a truck traveling 75 km/h. How long will it take the car to reach the truck?

**Physics**

def of average velocity = t^-1 (x - x0) (average velocity = t^-1(x-x0))t=(avearge velocity)t + x0= x - x0 + x0 = x = (average velocity)t + x0 x = (average velocity)t + x0 def of average velocity were costant acceleration is assumed = 2^-1(v0 + v) plug into x = (average velocit...

**Physics**

def of average velocity = t^-1 (x - x0) (average velocity = t^-1(x-x0))t=(avearge velocity)t + x0= x - x0 + x0 = x = (average velocity)t + x0 x = (average velocity)t + x0 def of average velocity were costant acceleration is assumed = 2^-1(v0 + v) plug into x = (average velocit...

**Sarah**

they got it in cm so 17.6 cm

**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 hori...

**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=f...

**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!

**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...

**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.

**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 taht will poduce standing waves on the string? Name at least one wavelenght that would not produce a stan...

**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?

**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))

**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 univera...

**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 accel...

**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 accel...

**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" adn allowed to roll down. For a bigger thrill you might wish the car to be ...

**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 ...

**Physics**

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

**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...

**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 ?

**physics**

please tell me if thsi si correct Two equal charges are seperated 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 3.6...

**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 = 0.7...

**physics**

ok, thanks

**physics**

is it .24 amps?

**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?

**physics**

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

**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...

**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...

**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 ba...

**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 ch...

**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

**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...

**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 ...

**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 con...

**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. nonconducto...

**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?

**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) =...

**physics**

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

**physics**

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

**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...

**physics**

so, how would i write it out? = -0.544 - -3.40 ????????

**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...

**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

**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 en...

**physics**

is this done correctly? A step-down transformer has 16000 turns on the primary adn 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*N...

**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 teh 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...

**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 differ...

**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

**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 illumina...

**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?

**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!

**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

**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 adn increasing teh number of coils b. increasing the current and reducing the number of coils c. reducing teh number of c...

**physics**

then it's A?

**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 ...

**physics**

thanks!

**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 ...

**physics**

i'm still getting C as the answer to this one drwl said its wrong When a positive charge moves in teh 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 sh...

**physics**

ok, :)

**physics**

nevermind i think its A can you check that?

**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 adn distnace b. charge adn mass c. Coulomb constant and mass d. elementary charge adn radius

**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 ...

**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

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