# Recent content by soupastupid

1. ### Kirchoff rule

Homework Statement write two independent equations using kirchoff rule to describe the circuit. Homework Equations V=IR Emf = IR The Attempt at a Solution The answer is emf2 -I1R3-I2R2-I1R1 = 0 (ok i have questions here: why is it I1R1? shouldnt it be I4R1?) and...
2. ### One voltage, 3 resistors

Homework Statement A circuit with one 5V and 3 resistors in parallel. What is the voltage across one of the resistors? Homework Equations V=IR The Attempt at a Solution 5/3 V?? or should i put R1 = 5V/I -R2-R3 V how do we get voltage across one of the resistors without...
3. ### Intergration Dipole

wats the R for V_a? wats the R for V_p? are they different? i think the R for V_a is ((s/2)^2 + d^2 ) )^ (1/2) but for V_p.... is it just s/2? if thats true i dont think i will get 0 for \DeltaV = V_p - V_A
4. ### Intergration Dipole

Homework Statement We know the magnitude of the electric field at a location on the x axis and at a location on the y axis, if we are far from the dipole. (a) Find \DeltaV= V_p - V_a along a line perpendicular to the axis of a dipole. Do it two ways: from superposition of V due to the two...
5. ### 2 Protons

Homework Statement He2+ 2 protons and 2 neutrons Homework Equations E = Kq/r^2 The Attempt at a Solution to get q do square the charges of the proton? or do I multipy it by 2
6. ### Unwinding Cylinder-Dynamics

im having trouble with part c it says its a yoyo and the string is wrapped around the axis and the radius casing >>>> radius of axis but i didnt that would matter because the string is wrapped around the axis but then the problem says I >>>> m(r_axis)^2 and then i go ...
7. ### Unwinding Cylinder-Dynamics

is that right? now that im looking at the problem more if T = mg shouldnt a_y equal to 0?
8. ### Unwinding Cylinder-Dynamics

ok for vertical a in the -y direction a_y = ( -gmr^2 ) / (I + mr^2) i dont see T in the equation so but it has to affect a_y but i do see I and if i make that equal to 0 i get a_y = -g WOWOW thats amazing thanks!
9. ### Unwinding Cylinder-Dynamics

ur right i contradicted myself anyway my logic tells me if t = 0, there is no tension and the object should just fall and so -y direction its a=g (linear) but the equations tells me otherwise that when t = 0 a = 0 (as seen in picture) that does not make sense to me...
10. ### Unwinding Cylinder-Dynamics

im having trouble with part B i think when t=0, a = 0 because if I goes to zero, t no longer does work on rotation but does work on linear acceleration but if the tension goes to 0 then the object will continue to spin but simply fall in the -y direction due to gravity right?
11. ### Unwinding Cylinder-Dynamics

Unwinding Cylinder--Dynamics Homework Statement A cylinder with a moment of inertia I (about its axis of symmetry), mass m, and radius r has a massless string wrapped around it which is tied to the ceiling (Intro 1 figure) . At time t=0 the cylinder is released from rest at height h...
12. ### Moving two blocks connected by a spring

what are you trying to say? the initial energy = 0 becuz the objects are at rest and spring is at its natural lenght so therefore the final energy is K + U which is equal to Wd that? and so .5m(v_1f)^2+.5m(v_2f)^2-.5kx^2 = (100N/m)(.08m) KE m1 KE m2...
13. ### Moving two blocks connected by a spring

Wd = (5N)(.08m)
14. ### Moving two blocks connected by a spring

Homework Statement m_1, v_1f m_2, v_2f m_2 = m_1 = m Homework Equations KE = .5mv^2 W = F*d spring: F= -kx pot energy = PE = -.5kx^2 The Attempt at a Solution A) K + U = .5m(v_1f)^2 + .5m(v_2f)^2 - .5kx^2 .5(.1kg)(v_1f)^2 + .5(.1kg)(v_2f)^2 -.5(100N/m)(.02m)^2 B) ...
15. ### The Rotational Kinetic Energy of the Earth

Homework Statement The Earth can be approximated as a sphere of uniform density, rotating on its axis once a day. The mass of the Earth is 5.97×10^24 kg, the radius of the Earth is 6.38×10^6 m, and the period of rotation for the Earth is 24.0 hrs. What is the moment of inertia of the...