Recent content by badaboom

but how does that j5 get up there?

Homework Statement I need to find the total impedance in a circuit that has: j60 ohms, 30 ohms, -j60 ohms and 20 ohms in parallel Homework Equations Ztotal=1/(Z1+ Z2+ Zn) The Attempt at a Solution I've tried doing this, but what I think is the -j60 and the j60 should cancel...

So I've made a circuit that lights up a light bulb whenever it's dark. I did this using a photoresistor and it is working. However, I have a relay switch with a 9V battery and a 7.2V lightbulb. When it was supposed to turn on, it lasted a couple of minutes and the battery is now dead. Should I...

Homework Statement Design a rectifier with a zener diode that satisfies the following: Primary voltage = 120V @ 60Hz VDC = 12V IR2 = 100 mA (R2 being the load) Vr(R2) <= .3V Homework Equations C=IDC/(2fVr) IDC=IR3 + IR1 The Attempt at a Solution I tried calculating the...

then the moment of inertia of the ring is 349.125. Are the other values I got correct? thank you

Homework Statement Suppose we rotate a grapefruit and a metal ring on a dining table with a smooth surface. Grapefruit has a volume of 575 cm3 and density of 0.4 g/cm3, while the ring has mass of 57 g, length of 2 cm and area of 38.5 cm2. Determine A. Moment of inertia of each of the...

pleaseeeeeeeeeeeeeeee

Homework Statement The bar AB is rotating with an angular velocity w=10rad/s. Determine the velocity of the piston C at the instant θ = 45. Provide the vector solution and the solution with the instantaneous center of zero velocity Homework Equations Vb = Va + w x r(b/a) Vc = Vb + w x...

ok, so what I have is the astronaut can continue for 9.4395 seconds, the angular velocity of the astronaut is 4.0118 rad/s^2, the normal acceleration would be 3.6125t^2 and tangencial acceleration is 8.5 rad/s^2. Does that seem about right? Thank you!

ok, then the time is 9.4395 and the velocity 4.0118?

ft/s^2, but is what I did right?

I've only used g to get 98.1, and the time is always in seconds. Do you think the answer I got is wrong?

Ok, I think I got it, sqrt(72.25 + 13.05t^4) has to equal 10g(98.1). I tried to find the value of t and got 5.201s, isn't that too small for this exercise?

ok, then the angular velocity is the function 0.425t. But I still don't know how to relate that with the acceleration...

angular velocity is V/r, is that V the one given to me, Vo?