Recent content by dannee

Homework Statement Positive charge Q uniformly distributed in a ball with radius R, which is located at the beginning of X axis. Positive point charge Q is located on the X axis on R=2. what is the size of the electric field in R/2? Homework Equations The Attempt at a Solution...

given the following Probability density function: f x,y(x,y) = { 0.5, ( 0<y<1, 2y-x<2, 2y+x<2 } 0, else and i need to find f z(z) while z=y-x i got really confused while trying to calculate the borders of x and y for the integration. i would be really thankful for someone explaining...

thanks !

Homework Statement i added a photo of a move of limit of function. can anyone please explain this move ? step by step.. i can't understand it thanks in advance ! Homework Equations The Attempt at a Solution

sure, force works on the center of mass therefore r=0.5L linear acceleration is with minus sign since it gets the rod down, means: T=m(g-a) a = alpha * 0.5L = 0.75g then T=0.25g wow, you have no idea how grateful i am, and i actually understand the subject better now. thanks !

Homework Statement if i have 2 spheres, one big sphere and one small (R>r), both are rolling from the same point down the way. at the end of the way, which sphere would have bigger speed? i thought the smaller sphere would have, since, angular acceleration = (f * r ) / I = f /...

that's a formula which i familiar with. alpha = a/r, means: 3g/2L = a/L, a= 3g/2 now i go back to coordinate y: tension-mg=ma, tension=m(g+a), tension=m*2.5g but i think I've missed something again as the answer is 0.25mg ? many many thanks for the help !

i think i got it, F=mg on the center of rod, then: torque=mg*0.5L then alpha = (0.5 * mg * L) / (0.5 * m * L^2) means alpha = (1/L) where do i go from here?

that's right, 8 * 3(m2*r^2), i refer the moment of wheel is (m1*r^2)/2 and sum them, but the correct answer is (3m2/8 + m1) * r^2

Homework Statement i've attched a picture of the wheel, which need to calculate moment of intertia with respect to 8 rods. i've tried to use stiener rule but it's not getting the answer, moment of wheel is (m1*r^2)/2 moment of rod is (m2*r^2/3) i use the rule i total = icm + mr^2...

sum of force coordinate y: T(tension of wire)-mg

Torque = Force * (L/2)

hey, thanks again for your help when I used 'T' symbol i meant for the tendency, not torque :) i'm still not so familiar with the subject. is it legal to use the equal torque=I*alpha,torque=F*r -> F*r=I*alpha ? Moment of Inertia is (m*L^2)/3, then again I'm stucking with equation...

a=(r * F)/I a=(mg-T)/(0.33*m*r) i don't know how to go from here

should i use r x F = I * a ? it leaves me with a = equaltion with t, r and mg but the answer should be only with mg