In analyzing distances by apply ing the physics of gravitational forces, an astronomer has obtained the expression
r= √1/([1/140×10^9 meter]^2 - [1/208×10^9]^2)
use your calculator to evaluate r. view available hint(s)
(a) 3.87 x 10-12 meter
(b) 1.72× 1011 meter
(c) 2.58 x 1011 meter
(d) 1.49 x 1011 meter

Space-time metric ds2= -dt2+at2dx2+bt2dy2+ct2dz2 (a)how does the area of a rectangle with vertices at ( x=0, y=0, z=0 ), (1,0,0 ), ( 0,1,0 ) and (1,1,0 ) changes with time? (b) if a photon moving in the x direction starts from the origin at t=1, when does it reach x=l? (ds=0 for the trajectory of a photon.) (c) the proper time for a particle is defined by cd=ds. what is the proper time for a particle to move along the trajectory ( x(t)=t, y(t)=0, z(t)=0 ) from t=0 to 1 ? what is the condition on the parameter a so that the velocity of the particle never exceeds the speed of light ?

If y gets smaller as x gets bigger and y have an relationship?

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? your