Thursday

July 31, 2014

July 31, 2014

Total # Posts: 32

**Physics**

Thanks Jack Package :) My job here is done :D

**Physics**

so, t12 is just pi*sqrt(m/k) really? :/

**Physics**

yes. convert everything to basic SI units.... HAS ANYBODY got t12? :/

**Physics**

Someone help with the t12? Please?

**Physics**

Phy? F(t)=m*a_x(t)=-F0+(t/ts-1)*F1 =>ax(t)=-F0/m+(t/ts-1)*F1/m integrating from 0->t vx(t)-vx(0)=-F0/m*t+(t^2/(2*ts)-t)*F1/m you get Vo from here by putting t=0. Now, Vx(t)=Vx(0)-F0/m*t+(t^2/(2*ts)-t)*F1/m Integrating between 0->t We get x(t)-x(0)=Vx(0)*t-F0/m*t^2/2+(...

**Physics**

The soln is simple. Try and read and understand it? It's too large to explain! can you guys give me t12?? solve the equation I gave: 1/2*k*(x_1)^2=(mu_k)*m*g*d

**Physics**

if you want to know how to solve the airliner problem.... since I can't input the link here... just type exactly this - "mit ocw 8.01 Airliner wheels locked landing" in google. Click on the first link... the link will be ending with something like ..../MIT8_01SC_...

**Physics**

KS. The mod(x_2-x_1) is actually really simple. All you need to do is this... 1/2*k*(x_1)^2=(mu_k)*m*g*d solve for d.... your d value will come equal to your x1...the magnitude I mean. This means the body starts moving and comes to rest at x_0=0 itself. :D So, your mod(x_2-x_1...

**Physics**

How does one get t_12 of the mass-spring system sum? I've got the other parts, for all other sums in case anybody needs help! :)

**Physics**

And guys, those of you who're not interested in the math portions. Let's be honest, Lewin's lectures are the important bit for you. It's difficult to maintain the honour code and get certs if you're not happy with math. I think, just watching Lewin's le...

**Physics**

Phy... your k is 40... F0 is obviously 0. I wasn't telling you because I thought it'd help you learn how to use wolfram better. Alas... Somebody help me with the Mass Spring sum? Everything else i've finished off :)

**Physics**

now type in F(x) in wolfram alpha... you'll get 3 roots... 1)x=0 and 2 more equal roots with opposite signs. the positive root must be chosen. Now in wolfram alpha type in Talyor Expansion( and type in your F(x)) at x=the positive root. the second term's coefficient is...

**Physics**

λ/4*(4*x^3-4*a^2*x)-b*x just input your values and solve for x.... the positive x0 value is the one required phy...

**Physics**

I'l give you the answers... but ask yourself, are you learning anything at all if you just fish for answers from strangers? Most of us come here if we get stuck!! F0=0,k=80...do try to find out T on your own?

**Physics**

no. Your equations are all messed up. U(x)=λ/4*(x2−a2)2+(b/2*x2) =>U'(x)=F(x)=λ/4*(4*x^3-4*a^2*x)-b*x Now using your lambda,a,b values: U'(x)=3x^3-40x hence: your roots are 0, 3.651483717, -3.651483717

**Physics**

are you sure about your x0? I'm getting x0=3.651483717 for you...

**Physics**

Some help with mass spring??? Please? ANd Pendulum??? See, for the mass spring problem... a)u_s*mg=kx1.... solve for x1.... but I'm not getting the other answers :(

**Physics**

Block on rotating disk is easy - I got option (a) :) solve for v: mv^2/R=umg....

**Physics**

give me your a,b,lambda values....

**Physics**

ss01 look.... its quite simple.... F0... comes to 0 for mine... and to get k, do the following: Since I don't know the values of a,b,lambda you have... F(x)=dU(x)/dx now type in F(x) in wolfram alpha... you'll get 3 roots... 1)x=0 and 2 more equal roots with opposite s...

**PHYSICS(HELP)**

Troll.... what's the angle of launch for the projectile??? like, suppose the string was cut at and angle alpha=70degrees, the launch angle is 70 degs too???

**PHYSICS(HELP)**

?????

**PHYSICS(HELP)**

ss01... tell me the answers/formulae for pendulum??? Block on rotating disk is easy - I got option (a) :) solve for v: mv^2/R=umg....

**PHYSICS(HELP)**

Listen... guys, I can help with all the problems barring the airliner, pendulum and mass-spring.... please let me know if you guys need any of the other answers and if you have solutions to the problems I'm stuck on?

**PHYSICS(HELP)**

The formula for the meteorite problem is: KE(initial)=KE(final) - GMm/(Radius of Earth) Can somebody please help with the aeroplane landing and Pendulum problems? :(

**english**

I thank you! I'm a non nativ speaker and really don't know what to do with that!

**english**

It's in my textbook... I think it had to be somethink with "But for..."

**english**

But have to stand at the beginning. That is what confused me...

**english**

Hey how can I say the sentence: "If you hadn't helped me, I would have made a complete mess of this." With the same meaning beginning with "But"??

**english**

thank you very much :)

**algebra 2**

solve this equation by using the quadratic (3x)^2-12(3x)+27=0

**health**

are they talking about all contract or just one I am a little confused

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