Recent content by gen x

But why we even need ground reference, if we have PE wire that return current back to transofrmer in case of fault? We have PE wire just to make RCD work?

Does house need PE wire connect to earth in garden, if yes why?

What mean grounding, connect pipe to ground wire(green or green-yellow wire) that coming from transformer or connect to Planet earth with wire? If pipes are metal and they lay under the ground, arent they grounded by itself to planet earth? When live line connect metal housing of some...

Both the main electrical cable (three-phase, line to neutral=230V, line to line =400V, 50Hz) and the water supply line(ppr pipe) are underground, below the earth in the garden, located next to each other, the main electrical power has damaged insulation, bare live line is exposed to a water leak...

Why is vector r a/p (lever arm) not perpendicular to force F? moment of point P must be: Mp= lever arm perpendicular to force F x force F

Net force=zero case: F1=10, F2=40, N=50 Moment at A=-10x2+40x1=+20Nm Moment at B= 10x2-50x4+40x5=+20Nm Net force = non zero: F1=10, F2=40, N=30 Moment at A=-10x2+40x1 =+20Nm Moment at B= 10x2-30x4+40x5 =+100Nm How do you get this equation?

Why as long net force= zero, moment at any point is the same but if net force= non zero, that is not case anymore? Here is simple example: Net force=zero case: F1=10, F2=40, N=50 Moment at A= +20Nm Moment at B=+20Nm Any point you choose you will get same moment.. Net force = non zero...

ω=7.292×10−5 rad/s R=6.378×106 m earth rotate around point A(CoM): ameasured=g−ac ac=ω^2R............. ac=(7.292×10−5)2×6.378×106≈0.034 m/s^2 ameasured=9.81−0.034≈9.78 m/s2 Earth rotate around point B, where x=50 000km: r=5.0×10^7+6.378×10^6=5.6378×10^7 m...

sl(t)=(vt+lcos(ωt),lsin(ωt)) for t=0, cos0=1,sin0=0 sl(0)=(l,0) .... x=l Translational velocity as a function of x: vtrans=(v,0) vtrans(x)=(v,0) Rotational velocity as a function of x: vlrot(t)=(−ωlsin(ωt),ωlcos(ωt)) t=0........vlrot(0)=(0,ωl) l=x.... vrot(x)=(0,ωx) Total...

How can rotation about points A, B and C be the same, acelometer placed on Earth will read different values? Rotation for points B and C must have net force= non zero.

vl(t)=vtranslation+vrotation vtranslation=(v,0) vrotation=(−ωlsin(ωt),ωlcos(ωt)) total velocity of the point at position l: vl(t)=(v−ωlsin(ωt),ωlcos(ωt)) stranslation=(vt,0) srotation=(lcos(ωt),lsin(ωt)) total position of the point l at time t: sl(t)=(vt+lcos(ωt),lsin(ωt) What is physical...

Why is force frame dependent? If acceleration is the same, and m is the same then why F is not equal? ..F=ma

vl(t) =ω⋅l vl(t)=v

I thought maybe " r" of local curvature in specific point. Doesn’t the centripetal force have to be the same in both reference frames?

math: Cf=m x 0^2 /r = 0 Yes that is good question. point t1 has centripetal force to the right toward center for frame fixed to center of wheel, but for ground frame centripetal force has different direction.