# Posts by Physics

Total # Posts: 430

**Physics!**

The cable supporting a 2100kg elevator has a maximum strength of 2.19×10^4 N. What maximum upward acceleration can it give the elevator without breaking?

**Physics**

One car has twice the maqss of a second car, but only half as much kiinetic energy. When both cars increase their speed by 7.0 s^-1 m, they then have the smae kinetic energy. What were the original speeds of the two cars? I got -16 or 2.4

**Physics**

I gues I'm looking at this the wrong way i do not understand the work you do to get to the answer Question: Find the air velocity of a plane that must have a realtive ground velocity of 250.0 h^-1 km norht if it encounters a wind pushing it toward the northeast at 75 h^-1 ...

**phys need help**

I typed in the answer for the direction (85 and 175) and they are both wrong according to the problem. I want to try 4.8 degrees since it says east of south, but I don't know though.

**phys**

An airplane is heading due south at a speed of 590 km/h. If a wind begins blowing from the southwest at a speed of 65.0 km/h (average). Calculate magnitude of the plane's velocity, relative to the ground. Calculate direction of the plane's velocity, relative to the ...

**phys**

At t= 0, a particle starts from rest at x= 0, y= 0, and moves in the xy plane with an acceleration ->a = (4.0ihat+ 3.0jhat)m/s^2. Assume t is in seconds. Determine the position of the particle as a function of time t. Express your answer in terms of the unit vectors ihat ...

**physics need to check**

I get 131.18 degrees and its wrong. I don't know what I am doing wrong.

**physics**

Let ->V1= -6.1 ihat + 8.0 jhat and ->V2 = -4.8 jhat + 4.2 ihat. Determine the direction of ->V1 counterclockwise from the +x direction Determine the direction of ->V2 counterclockwise from the +x direction

**physics**

If Vx= 8.00 units and Vy= -6.40 unis, determine (a)the magnitude and (b)direction of ->V(vector) b) theta= ______ degrees below the positive x-axis.

**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

**physics**

this is from that white book that i'm also using... the odd answers in the book are in the back in which this problem is one I belive

**physics**

At t= 0, a particle starts from rest at x= 0, y= 0, and moves in the xy plane with an acceleration ->a (vector) = (4.0ihat+ 3.0jhat)m/s^2. Assume t is in seconds. Determine the x component of velocity as a function of time t. Determine the y component of velocity as a ...

**physics**

can you walk me through this problem At what distance from the Earth will a spacecraft on the way to the Moon esperience zero net force due to these two bodies because the EArth and Mon pull with equal and opposite forces? mass of earth = m1 = 5.98 E 24 kg mass of moon = m2 = ...

**Physics**

I have no idea how to do this problem At what distance from the Earth will a spacecraft on the way to the Moon esperience zero net force due to these two bodies because the EArth and Mon pull with equal and opposite forces? there\'s no data in the question to use

**physics**

we can say that the force of gravity is equal to mass times acceleration were the acceleration is equal to gravity sense gravity is an acceleration because of newtons second law force = mass times acceleration hence Fg = mass times acceleration Fg = mass times gravity Fg = mg ...

**physics**

Calculate the acceleration due to gravity on the moon. The moon\'s radius is about 1.74 E 6 m and its mass is 7.35 E 22 kg ok aparently there\'s an easier way to do this I applied Newtons second law in the radial direction net force radial = m (radial acceleration) = ...

**physics**

If this question is asking for the normal force i got 100 n but i\'m not sure that is what it is asking for

**physics**

A rope of negligible mass passes over a puley of a negligible mass attached to the ceiling. One end of the rope is held by stdent A of mass 70 kg who is at rest on the floor. The opposite end of the rope is held by student B of mass 60 kg who is suspended at rest above the ...

**Physics**

not sure what the force of tension is equal to in this problem

**Physics**

Tarzan plans to corss a gorge by swinging in an arc form a hanging vine. If his arms are capable of exerting a force of 1400 N on the rope, what is the maximum speed he can tolerate at the lowest point of his swing? his mass is 80 kg and the vine is 4.8 m long. Ok If i\'m ...

**physics**

centripetal acceleration= friction m*w^2 r = mu*mg changing 50 rpm to rad/sec mu=w^2 r/g=(50*2PI/60)^2 * .12 which is not your answer. Check my thinking. ok I thought centripetal force was equal to m ac were ac is the centripetal acceleration which is equal to v^2 divided by r...

**Physics**

A coin is placced 12.0 cm from the axis of a roatating turntable of variable speed. When the speed of the turntable is slowly incraeased, the coin remains fixed on the turntable until a rate of 50 rpm is reached at which point the coin slides off. What is the coefficent of ...

**Physics**

A coin is placced 12.0 cm from the axis of a roatating turntable of variable speed. When the speed of the turntable is slowly incraeased, the coin remains fixed on the turntable until a rate of 50 rpm is reached at which point the coin slides off. What is the coefficent of ...

**physics**

Net Force Radial = m a radial = F radial = Ffr ma radial = Us Fn ma radial = Us m g cancel out mass a radial = Us g a radial = r^-1 v^2 r^-1 v^2 = Us g Us = (rg)^-1 V^2 don\'t see what I did wrong

**physics**

A coin is placced 12.0 cm from the axis of a roatating turntable of variable speed. When the speed of the turntable is slowly incraeased, the coin remains fixed on the turntable until a rate of 50 mph is reached at which point the coin slides off. What is the coefficent of ...

**physics**

so there is no static friction when a block is just sitting there and not moving with no applied force?

**physics**

what is the equal and opposite force the force of friction like if a block is at rest on a table static friction is stil exerted by the table onto the block keeping it from moving what is the equal and opposite force of this force?

**Physics**

A model rock is shot into the air. Once it starts to fall a parachute is deployed. Draw a free body diagram of the rocket with the parachute deployed ok well there is gravity does the parachute exert a force upward? onto what? what do i call this force?

**Physics**

yay i got it right thanks!

**Physics**

a mass (m1) on a smooth horizontal surface, connected by a thin cord that passes over a pulley to a second block (m2), which hangs vertically. If the acceleration is .098 m/s^2 and m1 is 1.0 kg how much must m1 must be to keep it at this acceleration I got 99 kg could you ...

**Physics**

oh wow so I\'m not sure how to do this if the net force in the y direciton is zero...

**Physics**

wait so if downards was negative the force of gravity on the first block would be -85 N the force of gravity on the seocnd block is - 30 N for problem (a) and the force of tension is equal and opposite to the force of gravity on the second block and is 30 N net force in y ...

**Physics**

I have a question 26. A box weighing 85 N rests on a table. A rope tied to the box runs vertically upward over a pully and a weight is hung form the other end. Detrmine the force that the table exerts on the box if the weight hanging on the other side of the pully weighs (a) ...

**Physics**

Is mass the one and only thing that produces a gravitional force???

**physics**

take a satalite going around the earth... what allows us to say net force (radial) = Fg = Fr = ma were the Fg is the force of gravity exerted on the satalite were Fr is radial force and ma is the mass and acceleration of the satalite ok I understand newtons second law but what...

**physics**

"The actual value of computed g, assuming no drag, also varies somewhat over the earth's surface due to the earth's spin (which causes a latitude-dependent centrifugal force to get subtracted), lack of a perfect spherical shape of the earth, and the proximity of ...

**physics**

Hi i'm doing that lab were you attach a weight to a tape which is also through a timer that puts marks on the tape at a given time interval ok I'm asked why is gravity different than on Earth? I don't rember the physics answer behind it I remeber Fg = G((m1 m1)/r^2...

**physics**

ok i saw the responses thanks still a little bit confused ok what variable is different or varaies in the sitations were you to walk say down a hill and feel that it is easier and when walking up a hill which is harder

**physics**

ok i'm doing a lab were walking different displacements I observed that the displacements were on different grades of steepness this would decrease the coefficent of kinetic friction?

**physics**

does the slope of a distance vs. time graph show the average velocity or the instaneous velocity I'm asked the question and don't know which one. I believe that it would be the instaneous value because the slope is refering to one point on the graph... not sure though

**physics**

hey wow thanks!!! I acutally understood just kind of werid because our book hasn't mentioned energy yet but I know about it from just regualr old physics I'm taking ap this year and doing the first chapters in order and it hasn't mentioned anything about energy yet...

**physics**

ok a person is holding onto a piece of string at the end of the string is a ball the person whrils it around in a circle i've been asked what's the mininum value of at the top of the circle (this is swung around in a verticle circle) what is the mininum value the ...

**physics (geometry bit)**

How to prove this? Similar triangles. Notice the upper angle in that photo is a right angle (ramp to Fn), yes and i agree right anlge in which the angle of Fn to the vertical is an angle complement to Fp and the vertical. ok so your saying that... angle Fn Fw is complement to ...

**physics (geometry bit)**

ohh ok um Fw is the gravity and Fp is the x component and Fn is the y component??? how come the x component is drawn in a weired location but we got the triangle now thanks!!!

**physics (geometry bit)**

what's fw and Fp

**physics (geometry bit)**

ha ha i copied the lnik instead of clicking on it i got it thanks

**physics (geometry bit)**

when i click on your link it bring me here h t t p : / / ww w . a n g e l f i r e . l yc o s . c o m / d o c / im ag e s / r l o a d b l oc k . j p g i noticed a different adress then the link

**physics (geometry bit)**

not for me =[ look... h t t p : / /i m g1 3 2 . i ma g e s h a c k. u s / i m g1 3 2 / 9 1 3 7 /c a p tu r e t q i. j p g could you try image shack upload (link below) I don't know why it wouldn't let me see it i captured the screen when i clicked on the link it's ...

**physics (geometry bit)**

link didn't got to image

**physics (geometry bit)**

your image didn't work

**physics**

i have a question in my book centripetal acceleration = r^-1 v^2 ok I agree but in my book acceelration is labeled as a vector but yet the velocity is not... Why?

**physics**

thanks for the help earlier just got a question I'm taking AP Physics B this year does that mean next year I would Take AP Physics C??? I don't know if the material in C convers the same material plus the additional calculus material or what??? Could I take AP Calculus...

**physics**

I just would like to make sure of something an object experiances a drag force when it travels through a medium like air or water... so dosen't every thing experience a drag force that is in motion because its moving through air?? So like if a person was walking do they ...

**physics**

also I was always told to use this equation when the velocity is small through the medium Fd = -bv were this is just a proportion also that other formula that is suppose to be used when there is a high velocity Fd = 2^-1 p v^2 A Cd v Ok what is exactly meant by high and low ...

**physics**

so I got a question about projectile motion take the example of shooting of a plastic air rocket into the air and asked to predict its landing point and how high it goes... ok I know how to do this... the thing is now were not neglecting air resistence and I don't know ...

**physics**

I don't see how this relationship works Fn sin theta = r^-1 m v^2 or more like why it works??? my text goes on to prove tan theta = (rg)^-1 v^2 which I understand how to rearange I just don't get where the first relationship comes from Fn sin theta = r^-1 m v^2 i get ...

**physics**

ok if a car is going around a bank curve my book is telling me there is an ideal spead were no friction is required at all for it to complete the banked turn it says that this occurs when the horizontal component of the normal force is equal to the radial acceleration why?

**physics**

I'm trying to rearange this equation for Mu s That is the greek letter Mu subscript s... the static coeficent of friction m2 = m1 sin theta - Mu s m1 cos theta ok I got this Mu s = -((m1 cos theta)^-1 (m2 - m1 sin theta)) ok I know that sin over cosine is tangent but I ...

**Tj**

a wire has a resistance of 10 ohms. The length of the wire is doubled, and its radius is also doubled. What is the new resistance?

**physics**

a block (mass m1) on a smooth horizontal surface, connected by a thin cord that passes over a pulley to as second block (m2), which hangs vertically. Ignore friction and the masses of the pulley and cord. If m1 = 13.0 kg and m2 = 6.0 kg determine the accleeration of each block...

**Algebra**

I took algebra two and there not really verticle asymptotes threr limits you have been lied to which you should be used to if you are going to a public high school All I remeber is you try to get them to cancel out and get removable discontinuties or something this was a long ...

**Algebra**

I think you mean the limits

**physics**

thank you so much

**physics**

m2a=m2g-m1a m2a+m1a=m2g a= m2g/(m1+m2) I got this m2a=m2g-m1a m2a + m1 a = m2g-m1a + m1 a m2 a + m1 a = m2g (m2 a + m1 a = m2g(m2 + m1)^-1 = a + a = (m2 + m1)^-1 m2g a + a = (m2 + m1)^-1 m2g 2a = (m2 + m1)^-1 m2g (2a = (m2 + m1)^-1 m2g)2^-1 = a = (2(m2 + m1))^-1 m2g a = (2(m2...

**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 ...

**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 ...

**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 ...

**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 ...

**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. ...

**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 ...

**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...