what is the gravitational force between two students who weight 50kg and are separated by 2.0m? 1.7 x 10^ -9 N 4.2 x 10 ^ -8 N 8.3 x 10 ^ -8 N. 1.7 x 10 ^ -7 N

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 ?

Slab pull” is a type of tectonic plate movement that occurs due to the forces of mantle convection and results in the subduction of the lithosphere true or false

Which describes increasing the efficiency of energy resource